Топ-100 ⓘ Free online encyclopedia. Did you know? page 117

ⓘ Free online encyclopedia. Did you know? page 117

                                               

184 (number)

Factors of 184: 2 3 x 23 Divisors of 184: 1, 2, 4, 8, 23, 46, 92, 184 184 is a refactorable number, or tau number, divisible by the count of its divisors. 184 has eight divisors, 8 being one of them 184 is a 32-gonal number In ternary, 184 is a K ...

                                               

185 (number)

185 is a 20-gonal number 185 is the sum of two square numbers in two different ways: 13 2 + 4 2 and 11 2 + 8 2 185 is an odd number 185 is an odious number 185 is the difference of 2 square numbers: 21 2 - 16 2 185 is a square-free number 185 is ...

                                               

186 (number)

There is no integer with exactly 186 coprimes less than it. 186 is a nontotient, nor is it ever the difference between an integer and the total of coprimes below it, thus also a noncototient 186 is a composite number 186 is a square-free number 1 ...

                                               

187 (number)

187 is an odd number 187 is a centered 31-gonal number 187 is the sum of 3 consecutive prime numbers: 59 + 61 + 67 187 is a composite number 187 is the sum of 9 consecutive primes: 7 + 11 + 13 + 17 + 19 + 23 + 29 + 31 + 37 187 is a deficient numb ...

                                               

189 (number)

189 is: an odd number a Harshad number in bases 3, 4, 5, 6, 7, 11, 13, 15 and 28 other bases. a centered cube number a heptagonal number a deficient number, as 131 is less than 189 a Kaprekar constant in base 2 a Ulam number palindromic in bases ...

                                               

19 (number)

19 is the natural number following 18 and preceding 20. It is a prime number. In English speech, the numbers 19 and 90 are sometimes confused, as they sound very similar.

                                               

191 (number)

191 is an odious number Gaussian prime Part of a prime quadruplet of four primes: 191, 193, 197, and 199 191 is a deficient number, as 1 is less than 191 191 is a lazy caterer, number of slices a circle can be made into 19 slices can divide into ...

                                               

193 (number)

193 is the sum of 2 square numbers: 12 2 + 7 2 or 144 + 49 193 is a Proth prime, as it is 3 × 2 6 + 1 193 is a lucky number 193 is a prime number 193 is a twin prime with 191 193 is a full reptend prime 193 is a happy number 193 is the difference ...

                                               

194 (number)

194 is a square-free number 194 is an odious number 194 is a composite number 194 is the number of irreducible representations of the Monster group. 194 is the smallest Markov number that is neither a Fibonacci number nor a Pell number 194 is the ...

                                               

195 (number)

195 is a square-free number 195 is an odd number 195 is a deficient number, as 141 is less than 195 195 is a sphenic number, in the middle of the prime quadruplet 191, 193, 197 and 199 195 is the sum of eleven consecutive primes: 3 + 5 + 7 + 11 + ...

                                               

196 (number)

A Lychrel number is a natural number which cannot form a palindromic number through the iterative process of repeatedly reversing its digits and adding the resulting numbers. 196 is the lowest number conjectured to be a Lychrel number in base 10; ...

                                               

197 (number)

197 is a Chen prime 197 is a strong prime 197 is the smallest prime number that is the sum of 7 consecutive primes: 17 + 19 + 23 + 29 + 31 + 37 + 41 197 is an odd number 197 is the sum of the first twelve prime numbers: 2 + 3 + 5 + 7 + 11 + 13 + ...

                                               

198 (number)

198 is a composite number 198 is a self number 198 is an abundant number, as 270 is greater than 198 198 is a 67-gonal number 198 is a Harshad number, divisible by the sum of its digits 198 is a practical number 198 is between the twin prime pair ...

                                               

199 (number)

199 is the sum of three consecutive primes: 61 + 67 + 71 199 is the fourth part of a prime quadruplet: 191, 193, 197, 199 199 is a permutable prime which can have its digits switched, and create another prime number 991 199 is a centered 33-gonal ...

                                               

2

2 is a number, numeral, and glyph. It is the natural number following 1 and preceding 3. It is the smallest and only even prime number. Because it forms the basis of a duality, it has religious and spiritual significance in many cultures.

                                               

2.147.483.647

The number 2.147.483.647 is the eighth Mersenne prime, equal to 2 31 − 1. It is one of only four known double Mersenne primes. The primality of this number was proven by Leonhard Euler, who reported the proof in a letter to Daniel Bernoulli writt ...

                                               

20 (number)

20 can be written as the sum of three Fibonacci numbers uniquely, i.e. 20 = 13 + 5 + 2. 20 is the smallest primitive abundant number. 20 is the number of moves quarter or half turns required to optimally solve a Rubiks Cube in the worst case. An ...

                                               

200 (number)

200 is the natural number following 199 and preceding 201. The number appears in the Padovan sequence, preceded by 86, 114, 151 it is the sum of the first two of these. The sum of Eulers totient function φx over the first twenty-five integers is ...

                                               

2000 (number)

2000 is a natural number following 1999 and preceding 2001. Two thousand is the highest number expressible using only two unmodified characters in Roman numerals MM.

                                               

205 (number)

205 is a lucky number, and a Wolstenholme number. On an infinite chessboard, a knight can reach exactly 205 squares within four moves. There are 205 different ways of forming a connected graph by adding six edges to a set of five labeled vertices.

                                               

21 (number)

21 is: an octagonal number. a Harshad number. a Motzkin number. a composite number, its proper divisors being 1, 3 and 7. a repdigit in base 4 111 4. a triangular number, because it is the sum of the first six natural numbers 1 + 2 + 3 + 4 + 5 + ...

                                               

210 (number)

210 is a composite number, an abundant number, and the product of the first four prime numbers 2, 3, 5, and 7, and thus a primorial. It is also the least common multiple of these four prime numbers. It is the sum of eight consecutive prime number ...

                                               

212 (number)

+212 is the code for international direct-dial phone calls to Morocco Bell 212 helicopter 212 Medea, a very large Main belt asteroid 212, a fragrance by Carolina Herrera "212" song, a 2011 song by Harlem rapper Azealia Banks Type 212 submarine Un ...

                                               

217 (number)

217 is the natural number following 216 and preceding 218. 217 is a centered hexagonal number, a 12-gonal number, a centered 36-gonal number, a Fermat pseudoprime to base 5, and a Blum integer. It is both the sum of two positive cubes and the dif ...

                                               

218 (number)

218 is the natural number following 217 and preceding 219. The code for international direct dial phone calls to Libya. 218TV a Libyan satellite channel. 218 is the number of inequivalent ways to color the 12 edges of a cube using at most 2 color ...

                                               

22 (number)

22 is an even composite number and a semiprime; its proper divisors are 1, 2, and 11. 22 is a Smith number in base 10. 22 divided by 7 approximates the irrational number π, the ratio of the circumference of a circle to its diameter. 22 is the num ...

                                               

222 (number)

222 is the natural number following 221 and preceding 223. It is a decimal repdigit and a strobogrammatic number meaning that it looks the same turned upside down on a calculator display. It is one of the numbers whose digit sum in decimal is the ...

                                               

229 (number)

229 is the natural number following 228 and preceding 230. It is a prime number, and a regular prime. It is also a full reptend prime, meaning that the decimal expansion of the unit fraction 1/229 repeats periodically with as long a period as pos ...

                                               

23 (number)

23 is the first prime p for which unique factorization of cyclotomic integers based on the p the root of unity breaks down. The natural logarithms of all positive integers lower than 23 are known to have binary BBP-type formulae. In the list of f ...

                                               

230 (number)

230 is: a nontotient since there is no integer with 230 coprimes below it. part of the 41-aliquot tree. a composite number, with its divisors being 2, 5, 10, 23, 46, and 115. a Harshad number in bases 2, 6, 10, 12, 23 and 16 other bases. palindro ...

                                               

237 (number)

237 is the natural number following 236 and preceding 238. 237 is a lucky number, and one of the numbers in Aronsons sequence. The 237th square pyramidal number, 4465475, is also a sum of two smaller square pyramidal numbers. There are only four ...

                                               

239 (number)

It is a prime number. The next is 241, with which it forms a pair of twin primes; hence, it is also a Chen prime. 239 is a Sophie Germain prime and a Newman–Shanks–Williams prime. It is an Eisenstein prime with no imaginary part and real part of ...

                                               

24 (number)

24 is the natural number following 23 and preceding 25. The SI prefix for 10 24 is yotta Y, and for 10 −24 i.e., the reciprocal of 10 24 yocto y. These numbers are the largest and smallest number to receive an SI prefix to date.

                                               

240 (number)

240 is: a Harshad number in bases 2, 3, 4, 5, 6, 7, 9, 10, 11, 13, 14, 15 and 73 other bases. a semiperfect number. a refactorable number or tau number, since it has 20 divisors and 20 divides 240. a pronic number since it can be expressed as the ...

                                               

243 (number)

243 is: the only 3-digit number that is a fifth power 3 5. a Harshad number. an 82-gonal number. a perfect totient number. the sum of five consecutive prime numbers 41 + 43 + 47 + 53 + 59.

                                               

25 (number)

It is a square number, being 5 2 = 5 × 5. It is one of two two-digit numbers whose square and higher powers of the number also ends in the same last two digits, e.g. 25 2 = 625, the other is 76. It is the smallest square that is also a sum of two ...

                                               

250 (number)

250 is the natural number following 249 and preceding 251. Two hundred fifty is also: SMTP status code for mail action completed. In Chinese slang, the number 250 means idiot In the Bible, the number of men rebelling against Moses, who were swall ...

                                               

255 (number)

Its factorization makes it a sphenic number. Since 255 = 2 8 – 1, it is a Mersenne number though not a pernicious one, and the fourth such number not to be a prime number. It is a perfect totient number, the smallest such number to be neither a p ...

                                               

256 (number)

256 is a composite number, with the factorization 256 = 2 8, which makes it a power of two. 256 is the lowest number that is a product of eight prime factors. 256 is 4 raised to the 4th power, so in tetration notation 256 is 2 4. 256 is a perfect ...

                                               

257 (number)

257 is a prime number of the form 2 n + 1, {\displaystyle 2^{2^{n}}+1,} specifically with n = 3, and therefore a Fermat prime. Thus a regular polygon with 257 sides is constructible with compass and unmarked straightedge. It is currently the seco ...

                                               

258 (number)

                                               

259 (number)

                                               

26 (number)

Twenty-six is a repdigit in base three 222 3 and in base twelve 22 12. In base ten, 26 is the smallest number that is not a palindrome to have a square 26 2 = 676 that is a palindrome.

                                               

260 (number)

260 is the natural number following 259 and preceding 261. It is also the magic constant of the n × n normal magic square and n -queens problem for n = 8, the size of an actual chess board. 260 is also the magic constant of the Franklin magic squ ...

                                               

261 (number)

There are six divisors of this number, the divisors being 1, 3, 9, 29, 87, and 261 itself. 261 is a deficient number, since 1 + 3 + 9 + 29 + 87 = 129 < 261. 261 is nonagonal number, Harshad number, unique period in base 2, and the number of po ...

                                               

263 (number)

263 is a balanced prime, an irregular prime, a Ramanujan prime, a Chen prime, and a safe prime. It is also a strictly non-palindromic number and a happy number.

                                               

269 (number)

269 is a twin prime, and a Ramanujan prime. It is the largest prime factor of 9! + 1 = 362881, and the smallest natural number that cannot be represented as the determinant of a 10 × 10 0.1-matrix.

                                               

27 (number)

In decimal, it is the first composite number not divisible by any of its digits. It is the radix base of the septemvigesimal positional numeral system. Within senary, one can readily test for divisibility by 43 decimal 27 by seeing if the last th ...

                                               

270 (number)

270 is a Harshad number in base 10 270 is the fourth number that is divisible by its average integer divisor Given 6 elements, there are 270 square permutations 270 is a harmonic divisor number The sum of the coprime counts for the first 29 integ ...

                                               

271 (number)

271 is a twin prime with 269, a cuban prime a prime number that is the difference of two consecutive cubes, and a centered hexagonal number. It is the smallest prime number bracketed on both sides by numbers divisible by cubes, and the smallest p ...

                                               

273 (number)

273 is the natural number following 272 and preceding 274. 273 is a figurate number, a truncated triangular pyramid number. There are 273 different ternary trees with five nodes.

                                               

276 (number)

276 is: the sum of twelve consecutive prime numbers 5 + 7 + 11 + 13 + 17 + 19 + 23 + 29 + 31 + 37 + 41 + 43. a Harshad number in bases 2, 3, 4, 5, 6, 7, 9, 11, 12, 13, 16 and 130 other bases. a hexagonal number. a centered pentagonal number. pali ...

                                               

277 (number)

277 is the 59th prime number, and is a regular prime. It is the smallest prime p such that the sum of the inverses of the primes up to p is greater than two. Since 59 is itself prime, 277 is a super-prime. 59 is also a super-prime it is the 17th ...

                                               

28 (number)

It is a composite number, its proper divisors being 1, 2, 4, 7, and 14. Twenty-eight is the second perfect number. As a perfect number, it is related to the Mersenne prime 7, since 2 3 − 1 2 3 − 1 = 28. The next perfect number is 496, the previou ...

                                               

280 (number)

The denominator of the eighth harmonic number, 280 is an octagonal number. There are 280 plane trees with ten nodes. As a consequence of this, 18 people around a round table can shake hands with each other in non-crossing ways, in 280 different w ...

                                               

281 (number)

281 is the 60th prime, twin prime with 283, Sophie Germain prime, sum of the first fourteen primes, sum of seven consecutive primes, Chen prime, Eisenstein prime with no imaginary part, centered decagonal number. 281 is the smallest prime p such ...

                                               

288 (number)

288 is a pentagonal pyramidal number, is 4 superfactorial since 288 = 1! 2! 3! 4! 288 is an untouchable number, a Harshad number in base 10 and base 12, an Achilles number, a 3-smooth number and a self number. Both 288 and 289 are powerful number ...

                                               

29 (number)

29 is a Markov number, appearing in the solutions to x 2 + y 2 + z 2 = 3 xyz: {2, 5, 29}, {2, 29, 169}, {5, 29, 433}, {29, 169, 14701}, etc. It is a Lucas prime, a Pell prime, and a tetranacci number. 29 is the smallest positive whole number that ...

                                               

290 (number)

The product of three primes, 290 is a sphenic number, and the sum of four consecutive primes 67 + 71 + 73 + 79. The sum of the squares of the divisors of 17 is 290. Not only is it a nontotient and a noncototient, it is also an untouchable number. ...

                                               

291 (number)

This number is the product of four divisors: 1, 3, 97 and 291. The sum of its proper divisors its aliquot sum is less than 291, making it a deficient number. Being the product of two prime numbers, 3 and 97, it is a semiprime. It is part of five ...

                                               

3

3 is a number, numeral, and glyph. It is the natural number following 2 and preceding 4, and is the smallest odd prime number. It has religious or cultural significance in many societies.

                                               

30 (number)

Thirty is the sum of the first four squares, which makes it a square pyramidal number. It is a primorial. 30 is the smallest sphenic number, and the smallest of the form 2 × 3 × r, where r is a prime greater than 3. 30 has an aliquot sum of 42; t ...

                                               

300 (number)

The number 300 is a triangular number and the sum of a pair of twin primes 149 + 151, as well as the sum of ten consecutive primes 13 + 17 + 19 + 23 + 29 + 31 + 37 + 41 + 43 + 47. It is palindromic in 3 consecutive bases: 300 10 = 606 7 = 454 8 = ...

                                               

31 (number)

31 is the number of regular polygons with an odd number of sides that are known to be constructible with compass and straightedge. 31 is the third Mersenne prime 2 5 − 1 and the eighth Mersenne prime exponent, as well as the fourth primorial prim ...

                                               

311 (number)

311 is the 64th prime; a twin prime with 313; an irregular prime; an Eisenstein prime with no imaginary part and real part of the form 3 n − 1 {\displaystyle 3n-1} ; a Gaussian prime with no imaginary part and real part of the form 4 n − 1 {\disp ...

                                               

32 (number)

32 is the smallest number n with exactly 7 solutions to the equation φx = n. It is also the sum of the totient function for the first ten integers. The fifth power of two, 32 is also a Leyland number since 2 4 + 4 2 = 32. 32 is the ninth happy nu ...

                                               

33 (number)

33 is: the smallest odd repdigit that is not a prime number. the largest positive integer that cannot be expressed as a sum of different triangular numbers. the sum of three cubes: 33 = 8866128975287528 3 + − 8778405442862239 3 + − 27361114688070 ...

                                               

34 (number)

34 is the ninth distinct semiprime and has four divisors including one and itself. Its neighbors, 33 and 35, also are distinct semiprimes, having four divisors each, and 34 is the smallest number to be surrounded by numbers with the same number o ...

                                               

35 (number)

35 is the sum of the first five triangular numbers, making it a tetrahedral number. 35 is the number of ways that three things can be selected from a set of seven unique things also known as the "combination of seven things taken three at a time" ...

                                               

353 (number)

In connection with Eulers sum of powers conjecture, 353 is the smallest number whose 4th power is equal to the sum of four other 4th powers, as discovered by R. Norrie in 1911: 353 4 = 30 4 + 120 4 + 272 4 + 315 4. {\displaystyle 353^{4}=30^{4}+1 ...

                                               

359 (number)

359° is one degree less than a full revolution 360°; this makes it a reflex angle. 359 is a Sophie Germain prime: 2359+1=719 also a Sophie Germain prime.

                                               

36 (number)

36 is both the square of six and a triangular number, making it a square triangular number. It is the smallest square triangular number other than one, and it is also the only triangular number other than one whose square root is also a triangula ...

                                               

360 (number)

A circle is divided into 360 degrees for the purpose of angular measurement. 360° = 2 π rad is also called a round angle. This choice of unit allows round angle to be divided into equal sectors measured in integer degrees rather than fractional d ...

                                               

363 (number)

363 is a palindromic number in bases 3, 10, 11 and 32. 363 is the sum of five consecutive powers of 3 + 9 + 27 + 81 + 243 deficient number. 363 is a 122-gonal number. 363 is a deficient number. 363 is a perfect totient number. It is an odd, compo ...

                                               

365 (number)

365 is a semiprime centered square number. It is also the fifth 38-gonal number. It is the smallest number which has more than one expression as a sum of consecutive square numbers: 365 = 13 2 + 14 2 {\displaystyle 365=13^{2}+14^{2}} 365 = 10 2 + ...

                                               

369 (number)

                                               

37 (number)

Thirty-seven is the 12th prime number, a permutable prime with 73 which is the 21st prime number. 37 is the fifth lucky prime, the first irregular prime, the third unique prime and the third cuban prime of the form p = x 3 − y 3 x − y x = y + 1. ...

                                               

38 (number)

38 is the sum of the squares of the first three primes. 38! − 1 yields 523 022 617 466 601 111 760 007 224 100 074 291 199 999 999, which is the 16th factorial prime. There is no answer to the equation φx = 38, making 38 a nontotient. There are o ...

                                               

384 (number)

384 is: the sum of a twin prime pair 191 + 193. an abundant number. a Harshad number in bases 2, 3, 4, 5, 7, 8, 9, 13, 17, and 62 other bases. the third 129-gonal number after 1, 129 and before 766 and 1275. the order of the hyperoctahedral group ...

                                               

39 (number)

Thirty-nine is the sum of consecutive primes 3 + 5 + 7 + 11 + 13 and also is the product of the first and the last of those consecutive primes. Among small semiprimes only three other integers 10, 155, and 371 share this attribute. 39 also is the ...

                                               

4

4 is a number, numeral, and glyph. It is the natural number following 3 and preceding 5. It is the smallest composite number, and is considered unlucky in many East Asian cultures.

                                               

4.294.967.295

The number 4.294.967.295 is an integer equal to 32 − 1. It is a perfect totient number. It follows 4.294.967.294 and precedes 4.294.967.296. It has a factorization of 3 ⋅ 5 ⋅ 17 ⋅ 257 ⋅ 65537 {\displaystyle 3\cdot 5\cdot 17\cdot 257\cdot 65537}.

                                               

40 (number)

40 is the natural number following 39 and preceding 41. Though the word is related to "four" 4, the spelling "forty" replaced "fourty" in the course of the 17th century and is now the standard form.

                                               

4000 (number)

4951 – centered pentagonal number 4922 – centered heptagonal number 4959 – nonagonal number 4933 – super-prime 4950 – triangular number, 12th Kaprekar number 4957 – sum of three and five consecutive primes 1637 + 1657 + 1663, 977 + 983 + 991 + 99 ...

                                               

41 (number)

an Eisenstein prime, with no imaginary part and real part of the form 3 n − 1. a Proth prime as it is 5 × 2 3 + 1. the smallest Sophie Germain prime to start a Cunningham chain of the first kind of three terms, {41, 83, 167}. the 12th supersingul ...

                                               

400 (number)

400 is the square of 20. 400 is the sum of the powers of 7 from 0 to 3, thus making it a repdigit in base 7 1111. A circle is divided into 400 grads, which is equal to 360 degrees and 2π radians. Degrees and radians are the SI accepted units. 400 ...

                                               

42 (number)

Forty-two 42 is a pronic number and an abundant number; its prime factorization 2 3 7 makes it the second sphenic number and also the second of the form 2 3 r. Additional properties of the number 42 include: It is a Catalan number. Consequently, ...

                                               

420 (number)

420 is: a zero of the Mertens function and is sparsely totient. a pronic number. the smallest number divisible by the numbers 1 to 7, and as a consequence of that it is a Harshad number in every base from 2 to 10 except base 5. the sum of the fir ...

                                               

43 (number)

Forty-three is the 14th smallest prime number. The previous is forty-one, with which it comprises a twin prime, and the next is forty-seven. 43 is the smallest prime that is not a Chen prime. It is also the third Wagstaff prime. 43 is the fourth ...

                                               

45 (number)

Forty-five is a triangular number, and in particular the sum of all the decimal digits 0 + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = 45. It is the smallest triangle number after 1 which can be written as the sum of two squares. It is also a hexagonal a ...

                                               

46 (number)

Forty-six is a Wedderburn-Etherington number, an enneagonal number and a centered triangular number. It is the sum of the totient function for the first twelve integers. 46 is the largest even integer that cannot be expressed as a sum of two abun ...

                                               

47 (number)

47 is the natural number following 46 and preceding 48. It is a prime number, and appears in popular culture as the adopted favorite number of Pomona College and an obsession of the hip hop collective Pro Era.

                                               

48 (number)

Forty-eight is the double factorial of 6, a highly composite number. Like all other multiples of 6, it is a semiperfect number. 48 is the second 17-gonal number. 48 is the smallest number with exactly ten divisors. There are 11 solutions to the e ...

                                               

495 (number)

495 is the natural number following 494 and preceding 496. It is a pentatope number {\displaystyle {\tbinom {12}{4}}}).

                                               

496 (number)

496 is most notable for being a perfect number, and one of the earliest numbers to be recognized as such. As a perfect number, it is tied to the Mersenne prime 31, 2 5 − 1, with 2 4 2 5 − 1 yielding 496. Also related to its being a perfect number ...

                                               

5

5 is a number, numeral, and glyph. It is the natural number following 4 and preceding 6, and is a prime number. It has attained significance throughout history in part because typical humans have five digits on each hand.

                                               

50 (number)

Fifty is the smallest number that is the sum of two non-zero square numbers in two distinct ways: 50 = 1 2 + 7 2 = 5 2 + 5 2. It is also the sum of three squares, 50 = 3 2 + 4 2 + 5 2, and the sum of four squares, 50 = 6 2 + 3 2 + 2 + 1 2. It is ...

                                               

5040 (number)

5040 is a factorial and one less than a square, making a Brown number pair, a superior highly composite number, a colossally abundant number, and the number of permutations of 4 items out of 10 choices.

                                               

500 (number)

Five hundred is also an HTTP status code for Internal Server Error the longest advertised distance in miles of the IndyCar Series and its premier race, the Indianapolis 500. a name of two different card games, see 500 card game for the trick taki ...

                                               

51 (number)

Fifty-one is a pentagonal number as well as a centered pentagonal number one of the few numbers to be both and an 18-gonal number and a Perrin number. It is also the 6th Motzkin number, telling the number of ways to draw non-intersecting chords b ...

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