18431131 has 2 divisors, whose sum is σ = 18431132. Its totient is φ = 18431130.

The previous prime is 18431059. The next prime is 18431167. The reversal of 18431131 is 13113481.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18431131 - 2⁹ = 18430619 is a prime.

It is a super-2 number, since 2×18431131² = 679413179878322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18431431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9215565 + 9215566.

It is an arithmetic number, because the mean of its divisors is an integer number (9215566).

Almost surely, 2^18431131 is an apocalyptic number.

18431131 is a deficient number, since it is larger than the sum of its proper divisors (1).

18431131 is an equidigital number, since it uses as much as digits as its factorization.

18431131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 288, while the sum is 22.

The square root of 18431131 is about 4293.1493102383. The cubic root of 18431131 is about 264.1500285518.

The spelling of 18431131 in words is "eighteen million, four hundred thirty-one thousand, one hundred thirty-one".