18316431 has 12 divisors (see below), whose sum is σ = 30236752. Its totient is φ = 10466496.

The previous prime is 18316427. The next prime is 18316439. The reversal of 18316431 is 13461381.

18316431 is a `hidden beast` number, since 18 + 3 + 1 + 643 + 1 = 666.

It is not a de Polignac number, because 18316431 - 2² = 18316427 is a prime.

It is a super-2 number, since 2×18316431² = 670983289155522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18316395 and 18316404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18316439) 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, 145306 + ... + 145431.

Almost surely, 2^18316431 is an apocalyptic number.

18316431 is a deficient number, since it is larger than the sum of its proper divisors (11920321).

18316431 is a wasteful number, since it uses less digits than its factorization.

18316431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290750 (or 290747 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 18316431 is about 4279.7699704540. The cubic root of 18316431 is about 263.6009380606.

The spelling of 18316431 in words is "eighteen million, three hundred sixteen thousand, four hundred thirty-one".