256885 has 8 divisors (see below), whose sum is σ = 312480. Its totient is φ = 202704.

The previous prime is 256877. The next prime is 256889. The reversal of 256885 is 588652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 256885 - 2³ = 256877 is a prime.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 256885.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 106 + ... + 724.

It is an arithmetic number, because the mean of its divisors is an integer number (39060).

2²⁵⁶⁸⁸⁵ is an apocalyptic number.

It is an amenable number.

256885 is a deficient number, since it is larger than the sum of its proper divisors (55595).

256885 is an equidigital number, since it uses as much as digits as its factorization.

256885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 707.

The product of its digits is 19200, while the sum is 34.

The square root of 256885 is about 506.8382384943. The cubic root of 256885 is about 63.5691271914.

The spelling of 256885 in words is "two hundred fifty-six thousand, eight hundred eighty-five".