256557176064 has 648 divisors, whose sum is σ = 945040195008. Its totient is φ = 68976230400.

The previous prime is 256557176053. The next prime is 256557176069. The reversal of 256557176064 is 460671755652.

It is a happy number.

256557176064 is a `hidden beast` number, since 2 + 5 + 6 + 5 + 571 + 7 + 6 + 0 + 64 = 666.

It is a tau number, because it is divible by the number of its divisors (648).

It is a super-3 number, since 3×256557176064³ (a number of 35 digits) contains 333 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 256557176064.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256557176069) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 51816789 + ... + 51821739.

Almost surely, 2^256557176064 is an apocalyptic number.

256557176064 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 256557176064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (472520097504).

256557176064 is an abundant number, since it is smaller than the sum of its proper divisors (688483018944).

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

256557176064 is an equidigital number, since it uses as much as digits as its factorization.

256557176064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5013 (or 4980 counting only the distinct ones).

The product of its (nonzero) digits is 10584000, while the sum is 54.

The spelling of 256557176064 in words is "two hundred fifty-six billion, five hundred fifty-seven million, one hundred seventy-six thousand, sixty-four".