256621004 has 12 divisors (see below), whose sum is σ = 450675624. Its totient is φ = 127856544.

The previous prime is 256620983. The next prime is 256621073. The reversal of 256621004 is 400126652.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 112217 + ... + 114480.

It is an arithmetic number, because the mean of its divisors is an integer number (37556302).

Almost surely, 2^256621004 is an apocalyptic number.

It is an amenable number.

256621004 is a deficient number, since it is larger than the sum of its proper divisors (194054620).

256621004 is a wasteful number, since it uses less digits than its factorization.

256621004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226984 (or 226982 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 256621004 is about 16019.3946202720. The cubic root of 256621004 is about 635.4734345231.

Adding to 256621004 its reverse (400126652), we get a palindrome (656747656).

The spelling of 256621004 in words is "two hundred fifty-six million, six hundred twenty-one thousand, four".