18116591 has 2 divisors, whose sum is σ = 18116592. Its totient is φ = 18116590.

The previous prime is 18116587. The next prime is 18116597. The reversal of 18116591 is 19561181.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18116591 - 2² = 18116587 is a prime.

It is a super-2 number, since 2×18116591² = 656421738922562, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18116597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9058295 + 9058296.

It is an arithmetic number, because the mean of its divisors is an integer number (9058296).

Almost surely, 2^18116591 is an apocalyptic number.

18116591 is a deficient number, since it is larger than the sum of its proper divisors (1).

18116591 is an equidigital number, since it uses as much as digits as its factorization.

18116591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2160, while the sum is 32.

The square root of 18116591 is about 4256.3588899434. The cubic root of 18116591 is about 262.6387644254.

The spelling of 18116591 in words is "eighteen million, one hundred sixteen thousand, five hundred ninety-one".