256811749560 has 256 divisors, whose sum is σ = 868008960000. Its totient is φ = 67527862272.

The previous prime is 256811749553. The next prime is 256811749627. The reversal of 256811749560 is 65947118652.

It is a happy number.

256811749560 is a `hidden beast` number, since 2 + 5 + 6 + 8 + 1 + 1 + 74 + 9 + 560 = 666.

256811749560 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 256811749497 and 256811749506.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 88646032 + ... + 88648928.

It is an arithmetic number, because the mean of its divisors is an integer number (3390660000).

Almost surely, 2^256811749560 is an apocalyptic number.

256811749560 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 256811749560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (434004480000).

256811749560 is an abundant number, since it is smaller than the sum of its proper divisors (611197210440).

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

256811749560 is a wasteful number, since it uses less digits than its factorization.

256811749560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4035 (or 4025 counting only the distinct ones).

The product of its (nonzero) digits is 3628800, while the sum is 54.

The spelling of 256811749560 in words is "two hundred fifty-six billion, eight hundred eleven million, seven hundred forty-nine thousand, five hundred sixty".