231915681 has 12 divisors (see below), whose sum is σ = 345795840. Its totient is φ = 149622840.

The previous prime is 231915659. The next prime is 231915701. The reversal of 231915681 is 186519132.

231915681 is a `hidden beast` number, since 2 + 3 + 1 + 91 + 568 + 1 = 666.

It is not a de Polignac number, because 231915681 - 2⁶ = 231915617 is a prime.

It is a super-2 number, since 2×231915681² = 107569766187387522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (231915611) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 415341 + ... + 415898.

It is an arithmetic number, because the mean of its divisors is an integer number (28816320).

Almost surely, 2^231915681 is an apocalyptic number.

It is an amenable number.

231915681 is a deficient number, since it is larger than the sum of its proper divisors (113880159).

231915681 is a wasteful number, since it uses less digits than its factorization.

231915681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 831276 (or 831273 counting only the distinct ones).

The product of its digits is 12960, while the sum is 36.

The square root of 231915681 is about 15228.7780534093. The cubic root of 231915681 is about 614.3889151163.

The spelling of 231915681 in words is "two hundred thirty-one million, nine hundred fifteen thousand, six hundred eighty-one".