256538 has 16 divisors (see below), whose sum is σ = 417120. Its totient is φ = 117936.

The previous prime is 256517. The next prime is 256541. The reversal of 256538 is 835652.

It is a super-5 number, since 5×256538⁵ (a number of 28 digits) contains 55555 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 256538.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1556 + ... + 1712.

It is an arithmetic number, because the mean of its divisors is an integer number (26070).

2²⁵⁶⁵³⁸ is an apocalyptic number.

256538 is a deficient number, since it is larger than the sum of its proper divisors (160582).

256538 is a wasteful number, since it uses less digits than its factorization.

256538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221.

The product of its digits is 7200, while the sum is 29.

The square root of 256538 is about 506.4958045236. The cubic root of 256538 is about 63.5404912560.

The spelling of 256538 in words is "two hundred fifty-six thousand, five hundred thirty-eight".