256561024566 has 48 divisors (see below), whose sum is σ = 644583082752. Its totient is φ = 66639225840.

The previous prime is 256561024501. The next prime is 256561024627. The reversal of 256561024566 is 665420165652.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25237050 + ... + 25247213.

It is an arithmetic number, because the mean of its divisors is an integer number (13428814224).

Almost surely, 2^256561024566 is an apocalyptic number.

256561024566 is an abundant number, since it is smaller than the sum of its proper divisors (388022058186).

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

256561024566 is a wasteful number, since it uses less digits than its factorization.

256561024566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50484297 (or 50484286 counting only the distinct ones).

The product of its (nonzero) digits is 2592000, while the sum is 48.

The spelling of 256561024566 in words is "two hundred fifty-six billion, five hundred sixty-one million, twenty-four thousand, five hundred sixty-six".