18913538 has 16 divisors (see below), whose sum is σ = 32956224. Its totient is φ = 7972560.

The previous prime is 18913529. The next prime is 18913541. The reversal of 18913538 is 83531981.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10220 + ... + 11927.

It is an arithmetic number, because the mean of its divisors is an integer number (2059764).

Almost surely, 2^18913538 is an apocalyptic number.

18913538 is a deficient number, since it is larger than the sum of its proper divisors (14042686).

18913538 is a wasteful number, since it uses less digits than its factorization.

18913538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22217.

The product of its digits is 25920, while the sum is 38.

The square root of 18913538 is about 4348.9697630588. The cubic root of 18913538 is about 266.4347855781.

The spelling of 18913538 in words is "eighteen million, nine hundred thirteen thousand, five hundred thirty-eight".