256457109715 has 4 divisors (see below), whose sum is σ = 307748531664. Its totient is φ = 205165687768.

The previous prime is 256457109683. The next prime is 256457109743. The reversal of 256457109715 is 517901754652.

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 256457109715 - 2⁵ = 256457109683 is a prime.

It is a Duffinian 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, 25645710967 + ... + 25645710976.

It is an arithmetic number, because the mean of its divisors is an integer number (76937132916).

Almost surely, 2^256457109715 is an apocalyptic number.

256457109715 is a deficient number, since it is larger than the sum of its proper divisors (51291421949).

256457109715 is an equidigital number, since it uses as much as digits as its factorization.

256457109715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51291421948.

The product of its (nonzero) digits is 2646000, while the sum is 52.

The spelling of 256457109715 in words is "two hundred fifty-six billion, four hundred fifty-seven million, one hundred nine thousand, seven hundred fifteen".