256520411757 has 128 divisors (see below), whose sum is σ = 415876032000. Its totient is φ = 155756390400.

The previous prime is 256520411699. The next prime is 256520411759. The reversal of 256520411757 is 757114025652.

256520411757 is a `hidden beast` number, since 2 + 5 + 6 + 520 + 4 + 117 + 5 + 7 = 666.

It is not a de Polignac number, because 256520411757 - 2⁸ = 256520411501 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256520411759) 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, 299323273 + ... + 299324129.

It is an arithmetic number, because the mean of its divisors is an integer number (3249031500).

Almost surely, 2^256520411757 is an apocalyptic number.

256520411757 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

256520411757 is a deficient number, since it is larger than the sum of its proper divisors (159355620243).

256520411757 is a wasteful number, since it uses less digits than its factorization.

256520411757 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1148 (or 1142 counting only the distinct ones).

The product of its (nonzero) digits is 588000, while the sum is 45.

The spelling of 256520411757 in words is "two hundred fifty-six billion, five hundred twenty million, four hundred eleven thousand, seven hundred fifty-seven".