256231731 has 24 divisors (see below), whose sum is σ = 399179664. Its totient is φ = 145770240.

The previous prime is 256231699. The next prime is 256231741. The reversal of 256231731 is 137132652.

It is not a de Polignac number, because 256231731 - 2⁵ = 256231699 is a prime.

It is a super-2 number, since 2×256231731² = 131309399942512722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (256231741) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30511 + ... + 37991.

It is an arithmetic number, because the mean of its divisors is an integer number (16632486).

Almost surely, 2^256231731 is an apocalyptic number.

256231731 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

256231731 is a deficient number, since it is larger than the sum of its proper divisors (142947933).

256231731 is a wasteful number, since it uses less digits than its factorization.

256231731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7731 (or 7724 counting only the distinct ones).

The product of its digits is 7560, while the sum is 30.

The square root of 256231731 is about 16007.2399557200. The cubic root of 256231731 is about 635.1519515667.

The spelling of 256231731 in words is "two hundred fifty-six million, two hundred thirty-one thousand, seven hundred thirty-one".