18855996209 has 2 divisors, whose sum is σ = 18855996210. Its totient is φ = 18855996208.

The previous prime is 18855996179. The next prime is 18855996311. The reversal of 18855996209 is 90269955881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17608493809 + 1247502400 = 132697^2 + 35320^2 .

It is a cyclic number.

It is not a de Polignac number, because 18855996209 - 2²⁰ = 18854947633 is a prime.

It is not a weakly prime, because it can be changed into another prime (18855995209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9427998104 + 9427998105.

It is an arithmetic number, because the mean of its divisors is an integer number (9427998105).

Almost surely, 2^18855996209 is an apocalyptic number.

It is an amenable number.

18855996209 is a deficient number, since it is larger than the sum of its proper divisors (1).

18855996209 is an equidigital number, since it uses as much as digits as its factorization.

18855996209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13996800, while the sum is 62.

The spelling of 18855996209 in words is "eighteen billion, eight hundred fifty-five million, nine hundred ninety-six thousand, two hundred nine".