18338809 has 2 divisors, whose sum is σ = 18338810. Its totient is φ = 18338808.

The previous prime is 18338783. The next prime is 18338833. The reversal of 18338809 is 90883381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9765625 + 8573184 = 3125^2 + 2928^2 .

It is a cyclic number.

It is not a de Polignac number, because 18338809 - 2⁷ = 18338681 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18338209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9169404 + 9169405.

It is an arithmetic number, because the mean of its divisors is an integer number (9169405).

Almost surely, 2^18338809 is an apocalyptic number.

It is an amenable number.

18338809 is a deficient number, since it is larger than the sum of its proper divisors (1).

18338809 is an equidigital number, since it uses as much as digits as its factorization.

18338809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 18338809 is about 4282.3835652590. The cubic root of 18338809 is about 263.7082453761.

The spelling of 18338809 in words is "eighteen million, three hundred thirty-eight thousand, eight hundred nine".