256671864 has 48 divisors (see below), whose sum is σ = 695892600. Its totient is φ = 85466304.

The previous prime is 256671853. The next prime is 256671871. The reversal of 256671864 is 468176652.

256671864 is a `hidden beast` number, since 2 + 566 + 7 + 1 + 86 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 123022 + ... + 125090.

Almost surely, 2^256671864 is an apocalyptic number.

256671864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

256671864 is an abundant number, since it is smaller than the sum of its proper divisors (439220736).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

256671864 is a wasteful number, since it uses less digits than its factorization.

256671864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3804 (or 3797 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 256671864 is about 16020.9819923749. The cubic root of 256671864 is about 635.5154134770.

It can be divided in two parts, 25 and 6671864, that added together give a square (6671889 = 2583²).

The spelling of 256671864 in words is "two hundred fifty-six million, six hundred seventy-one thousand, eight hundred sixty-four".