217

217 = 7 x 31.

217 is the ninth centered hexagonal (hex) number.

47 and 89 are primes, as is their concatenation: 4789. Inserting 0 between them transforms the prime into a power: 47089 = 217².

217 is 1001 in base 6 and 161 in base 12.

217 is the telephone area code covering much of central Illinois.

Source: Prime Curios!

331

331 is a prime number.

331 is a divisor of 31³ - 1.

331 is a centered pentagonal number and a centered hexagonal number (hex number).

331 is good, happy, lucky, and cuban.

The Best 331 Colleges by Robert Franek was published by Princeton Review in 2002.

Source: Prime Curios!

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?

37

37 is a prime number.

37 is the least number of 5th powers needed to represent every possible integer.

37 is the maximum number of regions into which 8 lines divide the plane.

The sum of the first 37 primes is a Fibonacci number.

37 has a representation as a sum of two squares: 37 = 1² + 6².

37 is the hypotenuse of a primitive Pythagorean triple: 37² = 12² + 35².

37 is a centered hexagonal number.

Abraham Lincoln was first elected to the U.S. House of Representatives at age 37.

Source: 37 Heaven!