18685388 has 6 divisors (see below), whose sum is σ = 32699436. Its totient is φ = 9342692.

The previous prime is 18685357. The next prime is 18685399. The reversal of 18685388 is 88358681.

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 as a sum of consecutive naturals, namely, 2335670 + ... + 2335677.

It is an arithmetic number, because the mean of its divisors is an integer number (5449906).

Almost surely, 2^18685388 is an apocalyptic number.

It is an amenable number.

18685388 is a deficient number, since it is larger than the sum of its proper divisors (14014048).

18685388 is a wasteful number, since it uses less digits than its factorization.

18685388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4671351 (or 4671349 counting only the distinct ones).

The product of its digits is 368640, while the sum is 47.

The square root of 18685388 is about 4322.6598293181. The cubic root of 18685388 is about 265.3591333436.

The spelling of 18685388 in words is "eighteen million, six hundred eighty-five thousand, three hundred eighty-eight".