256423566605 has 32 divisors (see below), whose sum is σ = 326432145408. Its totient is φ = 193029868800.

The previous prime is 256423566577. The next prime is 256423566613. The reversal of 256423566605 is 506665324652.

It is not a de Polignac number, because 256423566605 - 2²⁰ = 256422518029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9282644 + ... + 9310226.

It is an arithmetic number, because the mean of its divisors is an integer number (10201004544).

Almost surely, 2^256423566605 is an apocalyptic number.

It is an amenable number.

256423566605 is a deficient number, since it is larger than the sum of its proper divisors (70008578803).

256423566605 is a wasteful number, since it uses less digits than its factorization.

256423566605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29277.

The product of its (nonzero) digits is 7776000, while the sum is 50.

The spelling of 256423566605 in words is "two hundred fifty-six billion, four hundred twenty-three million, five hundred sixty-six thousand, six hundred five".