881

881 is a prime number.

881 has a representation as the sum of two squares: 16² + 25².

881 and 883 form a twin prime pair.

881 is the hypotenuse of a primitive Pythagorean triple: 881² = 369² + 800².

881 is the largest three-digit prime of any form ABC such that AB + C, A + BC, and A + B + C are prime: 88 + 1 = 89, 8 + 81 = 89, and 8 + 8 + 1 = 17.

881 is a 2007 Singaporean musical-comedy-drama film written and directed by Royston Tan.

Source: Prime Curios!

718

718 = 2 x 359

718 is the number of unlabeled topologies (topological spaces) with six elements.

718 is 23032 in base 4.

718 is a New York City telephone area code.

Source: What's Special About This Number?

57

57 = 3 x 19

57 is 111 in base 7.

57 is the sum of the 7th through 12th numbers: 7 + 8 + 9 + 10 + 11 + 12 = 57.

As a semiprime (a product of two primes), 57 is a Blum integer because its two prime factors, 3 and 19, are both Gaussian primes.

"57 Varieties" was the slogan of Pittsburgh's H. J. Heinz Company. In its early days, the company wanted to advertise the great number of choices of canned and bottled foods it offered for sale. Although the company had more than 60 products in 1892, the number 57 was chosen because the number "5" was Henry John Heinz's lucky number and the number "7" was his wife's lucky number.

Source: Wikipedia

194

194 = 2 x 97

194 has a representation as a sum of two squares: 194 = 5² + 13².

194 is the smallest number with five representations as a sum of three squares: 194 = 1² + 7² + 12² = 3² + 4² + 13² = 3² + 8² + 11² = 5² + 5² + 12² = 7² + 8² + 9².

194 Prokne is a large, dark, main-belt asteroid discovered in 1879.

Source: What's Special About This Number?

271

271 is a prime number.

269 and 271 form a twin prime pair.

271 is a Google number. The nth Google number is the first n-digit prime found in the decimal expansion of e. This sequence of numbers was originally featured in an unusual job ad placed by Google. The first few numbers in the sequence are

2,

71,

271,

4523,

74713,

904523, . . .

271 is a centered hexagonal number.

Source: Number Gossip