59

Number
$59$ (fifty-nine) is:


 * The $17$th prime number, after $2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53$


 * The $1$st of the $7$th pair of twin primes, with $61$


 * The $34$th positive integer after $2, 3, 4, 7, 8, \ldots, 44, 45, 46, 49, 50, 54, 55$ which cannot be expressed as the sum of distinct pentagonal numbers.


 * One of the prime factors of one of the terms of one of the $2$ representations of $635 \, 318 \, 657$ as the sum of $2$ fourth powers:
 * $635,318,657 = 59^4 + 158^4$

Also see