256121004 has 24 divisors (see below), whose sum is σ = 600122880. Its totient is φ = 85015504.

The previous prime is 256120981. The next prime is 256121023. The reversal of 256121004 is 400121652.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41784 + ... + 47519.

It is an arithmetic number, because the mean of its divisors is an integer number (25005120).

Almost surely, 2^256121004 is an apocalyptic number.

It is an amenable number.

256121004 is an abundant number, since it is smaller than the sum of its proper divisors (344001876).

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

256121004 is a wasteful number, since it uses less digits than its factorization.

256121004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89549 (or 89547 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 256121004 is about 16003.7809282682. The cubic root of 256121004 is about 635.0604476732.

Adding to 256121004 its reverse (400121652), we get a palindrome (656242656).

The spelling of 256121004 in words is "two hundred fifty-six million, one hundred twenty-one thousand, four".