256399904 has 24 divisors (see below), whose sum is σ = 522195660. Its totient is φ = 123778816.

The previous prime is 256399901. The next prime is 256399939. The reversal of 256399904 is 409993652.

It can be written as a sum of positive squares in 2 ways, for example, as 246490000 + 9909904 = 15700^2 + 3148^2 .

It is not an unprimeable number, because it can be changed into a prime (256399901) 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 3 ways as a sum of consecutive naturals, for example, 137219 + ... + 139074.

Almost surely, 2^256399904 is an apocalyptic number.

It is an amenable number.

256399904 is an abundant number, since it is smaller than the sum of its proper divisors (265795756).

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

256399904 is a wasteful number, since it uses less digits than its factorization.

256399904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276332 (or 276324 counting only the distinct ones).

The product of its (nonzero) digits is 524880, while the sum is 47.

The square root of 256399904 is about 16012.4921233392. The cubic root of 256399904 is about 635.2908779576.

The spelling of 256399904 in words is "two hundred fifty-six million, three hundred ninety-nine thousand, nine hundred four".