256636 has 12 divisors (see below), whose sum is σ = 455112. Its totient is φ = 126608.

The previous prime is 256609. The next prime is 256639. The reversal of 256636 is 636652.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256639) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55 + ... + 718.

It is an arithmetic number, because the mean of its divisors is an integer number (37926).

2²⁵⁶⁶³⁶ is an apocalyptic number.

It is an amenable number.

256636 is a deficient number, since it is larger than the sum of its proper divisors (198476).

256636 is a wasteful number, since it uses less digits than its factorization.

256636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 860 (or 858 counting only the distinct ones).

The product of its digits is 6480, while the sum is 28.

The square root of 256636 is about 506.5925384370. The cubic root of 256636 is about 63.5485812536.

The spelling of 256636 in words is "two hundred fifty-six thousand, six hundred thirty-six".