18112931 has 2 divisors, whose sum is σ = 18112932. Its totient is φ = 18112930.

The previous prime is 18112921. The next prime is 18112949. The reversal of 18112931 is 13921181.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18112931 is a prime.

It is a super-2 number, since 2×18112931² = 656156538821522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18112931.

It is not a weakly prime, because it can be changed into another prime (18112901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9056465 + 9056466.

It is an arithmetic number, because the mean of its divisors is an integer number (9056466).

Almost surely, 2^18112931 is an apocalyptic number.

18112931 is a deficient number, since it is larger than the sum of its proper divisors (1).

18112931 is an equidigital number, since it uses as much as digits as its factorization.

18112931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432, while the sum is 26.

The square root of 18112931 is about 4255.9289232787. The cubic root of 18112931 is about 262.6210767229.

The spelling of 18112931 in words is "eighteen million, one hundred twelve thousand, nine hundred thirty-one".