18056399 has 2 divisors, whose sum is σ = 18056400. Its totient is φ = 18056398.

The previous prime is 18056393. The next prime is 18056417. The reversal of 18056399 is 99365081.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18056399 - 2²⁴ = 1279183 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18056393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9028199 + 9028200.

It is an arithmetic number, because the mean of its divisors is an integer number (9028200).

Almost surely, 2^18056399 is an apocalyptic number.

18056399 is a deficient number, since it is larger than the sum of its proper divisors (1).

18056399 is an equidigital number, since it uses as much as digits as its factorization.

18056399 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 58320, while the sum is 41.

The square root of 18056399 is about 4249.2821746737. The cubic root of 18056399 is about 262.3475710660.

The spelling of 18056399 in words is "eighteen million, fifty-six thousand, three hundred ninety-nine".