256713189815 has 4 divisors (see below), whose sum is σ = 308055827784. Its totient is φ = 205370551848.

The previous prime is 256713189793. The next prime is 256713189827. The reversal of 256713189815 is 518981317652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 256713189815 - 2⁸ = 256713189559 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 3 ways as a sum of consecutive naturals, for example, 25671318977 + ... + 25671318986.

It is an arithmetic number, because the mean of its divisors is an integer number (77013956946).

Almost surely, 2^256713189815 is an apocalyptic number.

256713189815 is a deficient number, since it is larger than the sum of its proper divisors (51342637969).

256713189815 is an equidigital number, since it uses as much as digits as its factorization.

256713189815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51342637968.

The product of its digits is 3628800, while the sum is 56.

The spelling of 256713189815 in words is "two hundred fifty-six billion, seven hundred thirteen million, one hundred eighty-nine thousand, eight hundred fifteen".