18106591 has 2 divisors, whose sum is σ = 18106592. Its totient is φ = 18106590.

The previous prime is 18106567. The next prime is 18106597. The reversal of 18106591 is 19560181.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18106591 - 2⁷ = 18106463 is a prime.

It is a Chen prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18106597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9053295 + 9053296.

It is an arithmetic number, because the mean of its divisors is an integer number (9053296).

Almost surely, 2^18106591 is an apocalyptic number.

18106591 is a deficient number, since it is larger than the sum of its proper divisors (1).

18106591 is an equidigital number, since it uses as much as digits as its factorization.

18106591 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 31.

The square root of 18106591 is about 4255.1840148224. The cubic root of 18106591 is about 262.5904317299.

The spelling of 18106591 in words is "eighteen million, one hundred six thousand, five hundred ninety-one".