58 (fifty-eight) is the natural number following 57 and preceding 59.
Fifty-eight is the sum of the first seven prime numbers, an 11-gonal number, and a Smith number.
Given 58, the Mertens function returns 0.
There is no solution to the equation x – φ(x) = 58, making 58 a noncototient. However, the sum of the totient function for the first thirteen integers is 58.