256637328 has 80 divisors (see below), whose sum is σ = 689497536. Its totient is φ = 82183680.

The previous prime is 256637299. The next prime is 256637333. The reversal of 256637328 is 823736652.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 256637328.

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, 146538 + ... + 148278.

Almost surely, 2^256637328 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256637328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (344748768).

256637328 is an abundant number, since it is smaller than the sum of its proper divisors (432860208).

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

256637328 is a wasteful number, since it uses less digits than its factorization.

256637328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1872 (or 1866 counting only the distinct ones).

The product of its digits is 362880, while the sum is 42.

The square root of 256637328 is about 16019.9041195633. The cubic root of 256637328 is about 635.4869086714.

The spelling of 256637328 in words is "two hundred fifty-six million, six hundred thirty-seven thousand, three hundred twenty-eight".