929

929 is a prime number.

929 is the smallest palindromic prime whose cube can be expressed as the sum of three odd cubes: 929³ = 69³ + 447³ + 893³.

929 has a representation as a sum of two squares: 929 = 20² + 23².

929 is the hypotenuse of a primitive Pythagorean triple: 929² = 129² + 920².

The Mazda 929 automobile was introduced in 1973.

Source: Prime Curios!

799

799 = 17 x 47.

799 is the smallest number with a composite sum of digits (7 + 9 + 9 = 25) and a prime sum of cubes of digits (7³ + 9³ + 9³ = 1801).

799 is the smallest number whose sum of digits is 25.

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

799 is the sum of 11 positive fifth powers: 799 = 3⁵ + 3⁵ + 3⁵ + 2⁵ + 2⁵ + 1⁵ + 1⁵ + 1⁵ + 1⁵ + 1⁵ + 1⁵.

NGC 799 is a spiral galaxy in the constellation Cetus.

Source: Number Gossip

357

357 = 3 x 7 x 17.

357 is the only three-digit number such that 2*357³⁵⁷ - 1 is prime.

357 is the smallest three-digit number with its digits being three distinct odd primes that is not prime, nor do any of the permutations of its digits represent a prime number.

357 is the larger of the only two sphenic numbers (product of three distinct primes) consisting of three distinct prime digits.

357 is a divisor of 50² - 1.

The .357 Magnum is a revolver cartridge.

Source: Prime Curios!

93

93 = 3 x 31.

93 has the unique representation 93 = 2² + 5² + 8² as a sum of three squares.

93 is 1011101 in base 2 and 333 in base 5.

93 is a cake number. The nth cake number is the maximum number of pieces into which a (cylindrical) cake can be cut with n planar cuts. The first 10 cake numbers are 2, 4, 8, 15, 26, 42, 64, 93, 130, 176. There are 39 cake numbers below 10,000.

The chemical element niobium has one stable isotope, which has 93 neutrons.

Source: Number Gossip

1019

1019 is a prime number.

1019 is the number of twin prime pairs between 10,000 and 100,000.

1019 and 1021 form a twin prime pair.

1019 is a Sophie Germain prime because 2 x 1019 + 1 = 2039, and 2039 is also a prime.

The Broadway musical Damn Yankees had an initial run of 1019 performances.

Source: Prime Curios!

814

814 = 2 x 11 x 37.

29 circles divide the plane into at most 814 regions.

814 is a value of n such that n(n + 5) is a palindrome: 814 x 819 = 666666.

814 is a member of the sequence generated by starting with 1, then repeatedly reversing the digits and adding 13: 1, 14, 54, 98, . . . , 108, 814, 431, . . .

814 is the numerical designation of a naval air squadron of the Royal Navy Fleet Air Arm nicknamed the "Flying Tigers."

Source: What’s Special About This Number?

989

989 = 23 x 43.

989 is the smallest number so that it and its reverse are divisible by 43.

989 is 33131 in base 4 and 12424 in base 5.

989 is one of the integers generated by the following sieve: Keep first number, drop every second, keep first, drop every third, keep first, drop every fourth, and so on: 0, 1, 3, 5, 9, 11, 17, 21, 29, 33, . . . , 989, . . .

Halley's Comet was visible from Earth in the year 989.

Source: The On-Line Encyclopedia of Integer Sequences

479

479 is a prime number. Moreover, the differences between any two of its digits are also prime.

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

479 is the largest known prime number that cannot be represented as the sum of fewer than nineteen fourth powers.

Inserting 0 between adjacent digits of 479 produces a prime: 40709.

479 is the telephone area code serving northwestern Arkansas.

Source: Prime Curios!

506

506 = 2 x 11 x 23.

506 is a pronic number because it is the product of two consecutive integers: 22 x 23 = 506.

506 is the sum of the first eleven squares: 1² + 2² + . . . + 10² + 11² = 506 (which makes it a square pyramidal number).

506 is a hendecagonal number.

The telephone area code 506 covers the Canadian province of New Brunswick.

Source: Number Gossip

115

115 = 5 x 23.

115 = 23 x (2 + 3).

115 has a unique representation as a sum of three squares: 3² + 5² + 9² = 115.

115 is the smallest three-digit integer, abc, such that (abc)/(a*b*c) is prime: 115/5 = 23.

STS-115 was a space shuttle mission to the International Space Station flown by the space shuttle Atlantis on Sept. 9, 2006.

Source: Prime Curios!

611

611 = 13 x 47.

611 is a brilliant number. It is a semiprime (product of two primes) whose prime factors have the same number of decimal digits. These numbers are generally used for cryptographic purposes and for testing the performance of prime factoring programs.

611 is a number n such that n times n + 5 gives the concatenation of a number m and itself: 611 x 616 = 376376.

611 is a number with no zeroes that becomes a prime when any one digit is deleted: 61 and 11 are both primes.

For customers of some telephone companies in Canada and in the United States, 611 is the abbreviated dialing telephone number used to report a problem with telephone service, or with a payphone.

Source: The On-Line Encyclopedia of Integer Sequences

76

76 = 2² x 19.

76 has a unique representation as the sum of three squares: 76 = 2² + 6² + 6².

76 is the ninth Lucas number. Lucas numbers are the sequence of integers obtained when each successive element is the sum of the previous two elements, starting with 1 and 3.

76 is the number of integer partitions of 21 into distinct parts. The partitions of an integer are the number of ways of writing that integer as a sum of positive integers without regard to order with the constraint that all integers in a given partition are distinct.

Meredith Wilson's song "Seventy-six Trombones" is a highlight of the musical The Music Man.

Source: Wolfram MathWorld

320

320 = 2⁶ x 5.

320 has a representation as the sum of two squares: 8² + 16² = 320.

320 is the maximum determinant of a 10 x 10 matrix of 0s and 1s.

320 is 500 in base 8.

There are 320 rods in a mile; 320 is also the number of fluid ounces in a peck.

Source: Number Gossip

713

713 = 23 x 31.

713 is a brilliant number because it is a semiprime (product of two primes) whose prime factors have the same number of decimal digits.

713 is the sum of three consecutive prime numbers: 713 = 233 + 239 + 241.

713 is the number of commutative monoids of order 7 with four idempotents. A monoid is a set that is closed under an associative binary operation and has an identity element. Unlike a group, its elements need not have inverses.

Telephone area code 713 serves the Houston area.

Source: What’s Special About This Number?

227

227 is a prime number.

227 and 229 form a twin prime pair.

227 is the number of composite days in a year.

227 is the smallest three-digit prime that is changed into a composite number if any digit is deleted.

227 is the number of connected planar graphs with eight edges.

227 was an NBC sitcom set in Washington, D.C., that ran from 1985 to 1990.

Source: Number Gossip

581

581 = 7 x 83.

581 is the sum of three consecutive primes: 191 + 193 + 197 = 581.

581 has a base 3 representation (210112) that begins with its base 4 representation (21011).

581 becomes a prime when 3 is prefixed or appended: 3581 and 5813 are primes.

Gliese 581 c was the first discovered terrestrial exosolar planet in the habitable zone surrounding its star (where the surface temperatures might be similar to Earth's).

Source: Wikipedia