256972404640 has 48 divisors (see below), whose sum is σ = 693825495552. Its totient is φ = 88104824064.

The previous prime is 256972404607. The next prime is 256972404643. The reversal of 256972404640 is 46404279652.

It is not an unprimeable number, because it can be changed into a prime (256972404643) 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, 114718704 + ... + 114720943.

It is an arithmetic number, because the mean of its divisors is an integer number (14454697824).

Almost surely, 2^256972404640 is an apocalyptic number.

256972404640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256972404640 is an abundant number, since it is smaller than the sum of its proper divisors (436853090912).

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

256972404640 is a wasteful number, since it uses less digits than its factorization.

256972404640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229439669 (or 229439661 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 49.

The spelling of 256972404640 in words is "two hundred fifty-six billion, nine hundred seventy-two million, four hundred four thousand, six hundred forty".