256556 has 12 divisors (see below), whose sum is σ = 463680. Its totient is φ = 124080.

The previous prime is 256541. The next prime is 256561. The reversal of 256556 is 655652.

It is a super-2 number, since 2×256556² = 131641962272, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 911 + ... + 1158.

It is an arithmetic number, because the mean of its divisors is an integer number (38640).

2²⁵⁶⁵⁵⁶ is an apocalyptic number.

It is an amenable number.

256556 is a deficient number, since it is larger than the sum of its proper divisors (207124).

256556 is a wasteful number, since it uses less digits than its factorization.

256556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2104 (or 2102 counting only the distinct ones).

The product of its digits is 9000, while the sum is 29.

The square root of 256556 is about 506.5135733621. The cubic root of 256556 is about 63.5419773284.

The spelling of 256556 in words is "two hundred fifty-six thousand, five hundred fifty-six".