256636081680 has 320 divisors, whose sum is σ = 910597718016. Its totient is φ = 59219712000.

The previous prime is 256636081643. The next prime is 256636081703. The reversal of 256636081680 is 86180636652.

256636081680 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4966537 + ... + 5017943.

Almost surely, 2^256636081680 is an apocalyptic number.

256636081680 is a gapful number since it is divisible by the number (20) 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 256636081680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (455298859008).

256636081680 is an abundant number, since it is smaller than the sum of its proper divisors (653961636336).

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

256636081680 is a wasteful number, since it uses less digits than its factorization.

256636081680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51526 (or 51520 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 51.

The spelling of 256636081680 in words is "two hundred fifty-six billion, six hundred thirty-six million, eighty-one thousand, six hundred eighty".