• 58 can be written using four 4's:

See also 113.

---

58 has 4 divisors (see below), whose sum is σ = 90. Its totient is φ = 28.

The previous prime is 53. The next prime is 59. The reversal of 58 is 85.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 85 = 5 ⋅17.

It can be written as a sum of positive squares in only one way, i.e., 49 + 9 = 7^2 + 3^2 .

It is a Smith number, since the sum of its digits (13) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

58 is an idoneal number.

It is a magnanimous number.

It is an alternating number because its digits alternate between odd and even.

It is a plaindrome in base 6, base 7, base 10, base 12, base 13, base 15 and base 16.

It is a nialpdrome in base 4, base 8, base 9, base 11 and base 14.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13 + ... + 16.

58 is a deficient number, since it is larger than the sum of its proper divisors (32).

58 is a wasteful number, since it uses less digits than its factorization.

58 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31.

The product of its digits is 40, while the sum is 13.

The square root of 58 is about 7.6157731059. The cubic root of 58 is about 3.8708766406.

Subtracting from 58 its sum of digits (13), we obtain a triangular number (45 = T₉).

Subtracting 58 from its reverse (85), we obtain a cube (27 = 3³).

The spelling of 58 in words is "fifty-eight", and thus it is an aban number, an oban number, and an uban number.