256717172670 has 64 divisors (see below), whose sum is σ = 704263458816. Its totient is φ = 58667800320.

The previous prime is 256717172653. The next prime is 256717172791. The reversal of 256717172670 is 76271717652.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1110562 + ... + 1321658.

It is an arithmetic number, because the mean of its divisors is an integer number (11004116544).

Almost surely, 2^256717172670 is an apocalyptic number.

256717172670 is an abundant number, since it is smaller than the sum of its proper divisors (447546286146).

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

256717172670 is a wasteful number, since it uses less digits than its factorization.

256717172670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216905.

The product of its (nonzero) digits is 1728720, while the sum is 51.

The spelling of 256717172670 in words is "two hundred fifty-six billion, seven hundred seventeen million, one hundred seventy-two thousand, six hundred seventy".