18855309 has 24 divisors (see below), whose sum is σ = 27919360. Its totient is φ = 11309760.

The previous prime is 18855299. The next prime is 18855337. The reversal of 18855309 is 90355881.

It is not a de Polignac number, because 18855309 - 2⁷ = 18855181 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18855379) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 45897 + ... + 46305.

Almost surely, 2^18855309 is an apocalyptic number.

It is an amenable number.

18855309 is a deficient number, since it is larger than the sum of its proper divisors (9064051).

18855309 is a wasteful number, since it uses less digits than its factorization.

18855309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 561 (or 550 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 39.

The square root of 18855309 is about 4342.2700284529. The cubic root of 18855309 is about 266.1610807569.

The spelling of 18855309 in words is "eighteen million, eight hundred fifty-five thousand, three hundred nine".