256981920 has 96 divisors (see below), whose sum is σ = 871782912. Its totient is φ = 63255552.

The previous prime is 256981919. The next prime is 256981937. The reversal of 256981920 is 29189652.

256981920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (96).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14352 + ... + 26831.

It is an arithmetic number, because the mean of its divisors is an integer number (9081072).

Almost surely, 2^256981920 is an apocalyptic number.

256981920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256981920 is an abundant number, since it is smaller than the sum of its proper divisors (614800992).

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

256981920 is a wasteful number, since it uses less digits than its factorization.

256981920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41214 (or 41206 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 42.

The square root of 256981920 is about 16030.6556322566. The cubic root of 256981920 is about 635.7712083981.

The spelling of 256981920 in words is "two hundred fifty-six million, nine hundred eighty-one thousand, nine hundred twenty".