256407664 has 20 divisors (see below), whose sum is σ = 500084560. Its totient is φ = 127353600.

The previous prime is 256407659. The next prime is 256407673. The reversal of 256407664 is 466704652.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 50649 + ... + 55480.

It is an arithmetic number, because the mean of its divisors is an integer number (25004228).

Almost surely, 2^256407664 is an apocalyptic number.

It is an amenable number.

256407664 is a deficient number, since it is larger than the sum of its proper divisors (243676896).

256407664 is a wasteful number, since it uses less digits than its factorization.

256407664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106288 (or 106282 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 40.

The square root of 256407664 is about 16012.7344323198. The cubic root of 256407664 is about 635.2972869661.

The spelling of 256407664 in words is "two hundred fifty-six million, four hundred seven thousand, six hundred sixty-four".