18372921 has 16 divisors (see below), whose sum is σ = 28963200. Its totient is φ = 10136448.

The previous prime is 18372889. The next prime is 18372953. The reversal of 18372921 is 12927381.

It is an interprime number because it is at equal distance from previous prime (18372889) and next prime (18372953).

It is not a de Polignac number, because 18372921 - 2⁵ = 18372889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18372521) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 14476 + ... + 15693.

It is an arithmetic number, because the mean of its divisors is an integer number (1810200).

Almost surely, 2^18372921 is an apocalyptic number.

It is an amenable number.

18372921 is a deficient number, since it is larger than the sum of its proper divisors (10590279).

18372921 is a wasteful number, since it uses less digits than its factorization.

18372921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30208.

The product of its digits is 6048, while the sum is 33.

The square root of 18372921 is about 4286.3645435264. The cubic root of 18372921 is about 263.8716519136.

The spelling of 18372921 in words is "eighteen million, three hundred seventy-two thousand, nine hundred twenty-one".