256621452864 has 896 divisors, whose sum is σ = 883442073600. Its totient is φ = 64099123200.

The previous prime is 256621452851. The next prime is 256621452869. The reversal of 256621452864 is 468254126652.

It is not an unprimeable number, because it can be changed into a prime (256621452869) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2540806414 + ... + 2540806514.

Almost surely, 2^256621452864 is an apocalyptic number.

256621452864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256621452864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (441721036800).

256621452864 is an abundant number, since it is smaller than the sum of its proper divisors (626820620736).

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

256621452864 is a wasteful number, since it uses less digits than its factorization.

256621452864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291 (or 281 counting only the distinct ones).

The product of its digits is 5529600, while the sum is 51.

The spelling of 256621452864 in words is "two hundred fifty-six billion, six hundred twenty-one million, four hundred fifty-two thousand, eight hundred sixty-four".