18919385 has 12 divisors (see below), whose sum is σ = 24119148. Its totient is φ = 14244096.

The previous prime is 18919379. The next prime is 18919391. The reversal of 18919385 is 58391981.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18919379) and next prime (18919391).

It can be written as a sum of positive squares in 6 ways, for example, as 3717184 + 15202201 = 1928^2 + 3899^2 .

It is not a de Polignac number, because 18919385 - 2²⁴ = 2142169 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5102 + ... + 7991.

It is an arithmetic number, because the mean of its divisors is an integer number (2009929).

Almost surely, 2^18919385 is an apocalyptic number.

It is an amenable number.

18919385 is a deficient number, since it is larger than the sum of its proper divisors (5199763).

18919385 is a wasteful number, since it uses less digits than its factorization.

18919385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13132 (or 13115 counting only the distinct ones).

The product of its digits is 77760, while the sum is 44.

The square root of 18919385 is about 4349.6419392865. The cubic root of 18919385 is about 266.4622382892.

The spelling of 18919385 in words is "eighteen million, nine hundred nineteen thousand, three hundred eighty-five".