18521872 has 20 divisors (see below), whose sum is σ = 36237760. Its totient is φ = 9170208.

The previous prime is 18521861. The next prime is 18521897. The reversal of 18521872 is 27812581.

It is an alternating number because its digits alternate between odd and even.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3972 + ... + 7267.

It is an arithmetic number, because the mean of its divisors is an integer number (1811888).

Almost surely, 2^18521872 is an apocalyptic number.

It is an amenable number.

18521872 is a deficient number, since it is larger than the sum of its proper divisors (17715888).

18521872 is a wasteful number, since it uses less digits than its factorization.

18521872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11350 (or 11344 counting only the distinct ones).

The product of its digits is 8960, while the sum is 34.

The square root of 18521872 is about 4303.7044508191. The cubic root of 18521872 is about 264.5828109909.

The spelling of 18521872 in words is "eighteen million, five hundred twenty-one thousand, eight hundred seventy-two".