256587 has 12 divisors (see below), whose sum is σ = 357480. Its totient is φ = 163680.

The previous prime is 256579. The next prime is 256589. The reversal of 256587 is 785652.

It is a happy number.

It is not a de Polignac number, because 256587 - 2³ = 256579 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 256587.

It is not an unprimeable number, because it can be changed into a prime (256589) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2839 + ... + 2927.

It is an arithmetic number, because the mean of its divisors is an integer number (29790).

2²⁵⁶⁵⁸⁷ is an apocalyptic number.

256587 is a deficient number, since it is larger than the sum of its proper divisors (100893).

256587 is an equidigital number, since it uses as much as digits as its factorization.

256587 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154 (or 123 counting only the distinct ones).

The product of its digits is 16800, while the sum is 33.

The square root of 256587 is about 506.5441737894. The cubic root of 256587 is about 63.5445365123.

The spelling of 256587 in words is "two hundred fifty-six thousand, five hundred eighty-seven".