18131431 has 2 divisors, whose sum is σ = 18131432. Its totient is φ = 18131430.

The previous prime is 18131417. The next prime is 18131479. The reversal of 18131431 is 13413181.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18131431 - 2⁷ = 18131303 is a prime.

It is a super-2 number, since 2×18131431² = 657497580215522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18131411) 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, 9065715 + 9065716.

It is an arithmetic number, because the mean of its divisors is an integer number (9065716).

Almost surely, 2^18131431 is an apocalyptic number.

18131431 is a deficient number, since it is larger than the sum of its proper divisors (1).

18131431 is an equidigital number, since it uses as much as digits as its factorization.

18131431 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 18131431 is about 4258.1018071436. The cubic root of 18131431 is about 262.7104573750.

The spelling of 18131431 in words is "eighteen million, one hundred thirty-one thousand, four hundred thirty-one".