256685 has 16 divisors (see below), whose sum is σ = 362880. Its totient is φ = 171840.

The previous prime is 256661. The next prime is 256687. The reversal of 256685 is 586652.

It is a happy number.

It is not a de Polignac number, because 256685 - 2¹² = 252589 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256687) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 536 + ... + 894.

It is an arithmetic number, because the mean of its divisors is an integer number (22680).

2²⁵⁶⁶⁸⁵ is an apocalyptic number.

It is an amenable number.

256685 is a deficient number, since it is larger than the sum of its proper divisors (106195).

256685 is a wasteful number, since it uses less digits than its factorization.

256685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 388.

The product of its digits is 14400, while the sum is 32.

The square root of 256685 is about 506.6408984675. The cubic root of 256685 is about 63.5526254800.

The spelling of 256685 in words is "two hundred fifty-six thousand, six hundred eighty-five".