1137

1137 = 3 x 379.

1137 is the product of two primes, as are 1136 (2⁴ x 71) and 1138 (2 x 569).

1137 is a semiprime (product of two distinct primes), as are 1139 (17 x 67) and 1141 (7 x 163).

1137 is the maximum value of n so that there exist seven denominations of stamps so that every postage from 1 to n can be paid for with at most seven stamps (postage stamp problem). It is also the solution to the postage stamp problem for n denominations and seven stamps, for n = 7.

1137 in base 2 (binary) is palindromic: 10001110001.

1137 is 696 in base 13 and 393 in base 18.

Atlantic Records 1957 release 45-1137 featured "Rakin and Scrapin" by Dean Beard and the Crew Cats.

Source: What's Special About This Number?

72

72 = 2³ x 3².

72 is the sum of the first eight even numbers: 72 = 2 + 4 + 6 + 8 + 10 + 12 + 14 + 16.

72 is the sum of nine consecutive integers: 72 = 4 + 5 + 6 + 7 + 8 + 9 + 10 + 11 + 12.

72 has a representation as a sum of two squares: 72 = 6² + 6².

72 is 2200 in base 3, 200 in base 6, 110 in base 8, 66 in base 11, 44 in base 17, 33 in base 23, and 22 in base 35.

The normal human pulse rate is about 72 beats per second at rest.

The Cambodian alphabet, with 72 letters, is the longest in the world.

Source: Phillips, R. 2004. Numbers: Facts, Figures and Fiction. Badsey Publications.

469

469 = 7 x 67.

469 is a heptagonal number. 469 is also a centered hexagonal number.

469 is a value of n for which n! - 1 is a prime number.

469 is the sum of three distinct positive cubes: 469 = 7³ + 5³ + 1³.

Inserting a zero between adjacent digits makes 469 a prime number: 40609.

469 Argentina is a main-belt asteroid discovered in 1901.

Source: What's Special About This Number?

663

663 = 3 x 13 x 17.

663 is a number that cannot be written as a sum of three squares.

663 has the representation 663 = 3⁶ - 66.

663 is the generalized Catalan number C(15,3).

663 is the numerical equivalent of ONE on a touch-tone telephone.

Source: Number Gossip

144

144 = 2⁴ x 3².

144² = 12², a perfect square. If you reverse the digits, 21² = 441.

144 has a unique representation as a sum of three squares: 144 = 4² + 8² + 8².

144 is a square number. Divide it by 4 and you get 36, which is also square. Does this happen with any other square numbers?

144 is the 12th Fibonacci number.

144 is 99 in base 15.

The interior angles in a regular decagon measure 144 degrees. In counting objects, 144 is called a gross (a dozen dozens).

Source: WolframAlpha

843

843 = 3 x 281.

843 is the 14th Lucas number.

843 is a divisor of 53⁴ - 1.

843 is 31023 in base 4, 11333 in base 5, 3523 in base 6, 2313 in base 7, and 1513 in base 8, all ending in 3. 843 is 443 in base 14, 223 in base 20, and 123 in base 28.

843 is palindromic in base 2: 1101001011.

Telephone area code 843 covers coastal South Carolina, including Charleston, Myrtle Beach, and Hilton Head Island.

Source: WolframAlpha

700

700 = 2² x 5² x 7.

700 is the sum of four consecutive primes: 700 = 167 + 173 + 179 + 181.

700 is a number that cannot be written as a sum of three squares.

700 is 221221 in base 3 and 2020 in base 7.

700 is the number of n-bead necklaces with four colors, for n = 7.

The first known recorded use of the zero in Europe occurred in the year 700.

Source: Wikipedia

50

50 = 2 x 5².

50 = 8 + 9 + 10 + 11 + 12.

50 can be expressed as a sum of primes in two distinct ways such that all primes involved are consecutive: 50 = 2 + 5 + 7 + 17 + 19 = 3 + 11 + 13 + 23.

50 is the smallest number with two representations as a sum of two squares: 50 = 1² + 7² = 5² + 5².

50 is 1212 in base 3, 101 in base 7, and 55 in base 9.

The flag of the United States of America has 50 stars representing its 50 constituent states. If you count stars along the diagonals, you get the sum 1 + 3 + 5 + 7 + 9 + 9 + 7 + 5 + 3 + 1 = 50.

Source: Number Gossip

352

352 = 2⁵ x 11.

352 is the only number consisting of three distinct prime digits such that the first and third equal the third raised to the power of the second: 32 = 2⁵.

352 has a unique representation as a sum of three squares: 352 = 8² + 12² + 12².

352 is the maximum number of volumes into which 11 intersecting spheres can divide space.

352 is the maximum number of regions into which 26 lines can divide a plane.

352 is the number of n-Queens Problem solutions for n = 9.

Source: Prime Curios!

226

226 = 2 x 113.

226 is a centered pentagonal number.

226 has a representation as a sum of two squares: 226 = 1² + 15².

224² and 226² are the squares of two consecutive even numbers, where the squares each use the same digits: 224² = 50176 and 226² = 51076.

226 is 1401 in base 5 and 1014 in base 6.

Radium-226 is a radioactive decay product of uranium-238; radium-226 itself decays to form the inert gas radon-222.

Source: Numeropedia

950

950 = 2 x 5² x 19.

950 is the generalized Catalan number C(17, 3).

950 is 12300 in base 5, 4222 in base 6, 2525 in base 7, and 1666 in base 8.

Both 950 and 950² (902500) have the same initial digit and the same final digit.

950 KJR is Seattle's all sports radio station.

Source: What's Special About This Number?

510

510 = 2 x 3 x 5 x 17.

The concatenation of 510 with itself (510510) is the product of the first seven primes (2 x 3 x 5 x 7 x 11 x 13 x 17) and also the product of the seventh through tenth Fibonacci numbers (13 x 21 x 34 x 55).

510 is the number of binary rooted trees with 14 vertices.

510 is 626 in base 9, 424 in base 11, and 303 in base 13.

510 Mabella is an asteroid discovered in 1903.

Source: Prime Curios!

4329

4329 = 3² x 13 x 37.

4329 has two representations as a sum of two squares: 4329 = 27² + 60² = 45² + 48².

4329 is a divisor of 100³ - 1.

4329 is the only number n such that n, 2n, 4n, and 6n together contain every digit from 1 to 9 exactly twice: 4329, 8658, 17316, 25974.

IC4329 is a supercluster of galaxies found in the constellation Centaurus.

Source: What's Special About This Number?

402

402 = 2 x 3 x 67. As the product of three distinct primes, 402 is a sphenic number.

402 is the number of graphs with eight vertices and nine edges.

402 is 123 in base 19.

The digit 3 occurs in the 402nd position in the decimal expansion of pi.

402 is the telephone area code for Omaha, Nebraska.

Source: What's Special About This Number?

953

953 is a prime number.

953 is a Sophie Germain prime because 2 x 953 + 1 = 1907 is also a prime.

953 has a representation as a sum of two squares: 953 = 13² + 28².

953 is the hypotenuse of a primitive Pythagorean triple: 953² = 615² + 728².

953 is the largest prime factor of 54321.

953 Painleva is a main-belt asteroid discovered in 1921.

Source: What's Special About This Number?

432

432 = 2⁴ x 3³.

432 = 4 x 3³ x 2².

432 is the sum of four consecutive primes: 432 = 103 + 107 + 109 + 113.

432 +/- 1 are twin primes. Note the descending digits.

432 is 12300 in base 4, 2000 in base 6, 660 in base 8, 363 in base 11, and 300 in base 12.

432 is sometimes known as the "cycle of time" number.

Source: Prime Curios!