256399916 has 24 divisors (see below), whose sum is σ = 475717536. Its totient is φ = 120500480.

The previous prime is 256399901. The next prime is 256399939. The reversal of 256399916 is 619993652.

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 7 ways as a sum of consecutive naturals, for example, 61985 + ... + 65991.

It is an arithmetic number, because the mean of its divisors is an integer number (19821564).

Almost surely, 2^256399916 is an apocalyptic number.

It is an amenable number.

256399916 is a deficient number, since it is larger than the sum of its proper divisors (219317620).

256399916 is a wasteful number, since it uses less digits than its factorization.

256399916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4969 (or 4967 counting only the distinct ones).

The product of its digits is 787320, while the sum is 50.

The square root of 256399916 is about 16012.4924980466. The cubic root of 256399916 is about 635.2908878685.

The spelling of 256399916 in words is "two hundred fifty-six million, three hundred ninety-nine thousand, nine hundred sixteen".