256664564 has 24 divisors (see below), whose sum is σ = 484835400. Its totient is φ = 118185984.

The previous prime is 256664563. The next prime is 256664581. The reversal of 256664564 is 465466652.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1304164 + 255360400 = 1142^2 + 15980^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256664561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17852 + ... + 28844.

It is an arithmetic number, because the mean of its divisors is an integer number (20201475).

Almost surely, 2^256664564 is an apocalyptic number.

It is an amenable number.

256664564 is a deficient number, since it is larger than the sum of its proper divisors (228170836).

256664564 is a wasteful number, since it uses less digits than its factorization.

256664564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11459 (or 11457 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 44.

The square root of 256664564 is about 16020.7541645205. The cubic root of 256664564 is about 635.5093885257.

The spelling of 256664564 in words is "two hundred fifty-six million, six hundred sixty-four thousand, five hundred sixty-four".