18165431 has 2 divisors, whose sum is σ = 18165432. Its totient is φ = 18165430.

The previous prime is 18165391. The next prime is 18165439. The reversal of 18165431 is 13456181.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18165431 is a prime.

It is a super-2 number, since 2×18165431² = 659965766831522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18165394 and 18165403.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18165439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9082715 + 9082716.

It is an arithmetic number, because the mean of its divisors is an integer number (9082716).

Almost surely, 2^18165431 is an apocalyptic number.

18165431 is a deficient number, since it is larger than the sum of its proper divisors (1).

18165431 is an equidigital number, since it uses as much as digits as its factorization.

18165431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2880, while the sum is 29.

The square root of 18165431 is about 4262.0923265457. The cubic root of 18165431 is about 262.8745661019.

The spelling of 18165431 in words is "eighteen million, one hundred sixty-five thousand, four hundred thirty-one".