256715 has 4 divisors (see below), whose sum is σ = 308064. Its totient is φ = 205368.

The previous prime is 256699. The next prime is 256721. The reversal of 256715 is 517652.

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 256715 - 2⁴ = 256699 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, 25667 + ... + 25676.

It is an arithmetic number, because the mean of its divisors is an integer number (77016).

2²⁵⁶⁷¹⁵ is an apocalyptic number.

256715 is a deficient number, since it is larger than the sum of its proper divisors (51349).

256715 is an equidigital number, since it uses as much as digits as its factorization.

256715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51348.

The product of its digits is 2100, while the sum is 26.

The square root of 256715 is about 506.6705043714. The cubic root of 256715 is about 63.5551012831. Note that the first 3 decimals are identical.

The spelling of 256715 in words is "two hundred fifty-six thousand, seven hundred fifteen".