18668518 has 24 divisors (see below), whose sum is σ = 31669560. Its totient is φ = 8184960.

The previous prime is 18668513. The next prime is 18668549. The reversal of 18668518 is 81586681.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18668513) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17998 + ... + 19006.

It is an arithmetic number, because the mean of its divisors is an integer number (1319565).

Almost surely, 2^18668518 is an apocalyptic number.

18668518 is a deficient number, since it is larger than the sum of its proper divisors (13001042).

18668518 is a wasteful number, since it uses less digits than its factorization.

18668518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1080 (or 1051 counting only the distinct ones).

The product of its digits is 92160, while the sum is 43.

The square root of 18668518 is about 4320.7080438280. The cubic root of 18668518 is about 265.2792499523.

The spelling of 18668518 in words is "eighteen million, six hundred sixty-eight thousand, five hundred eighteen".