18904172 has 48 divisors (see below), whose sum is σ = 40427520. Its totient is φ = 7560000.

The previous prime is 18904169. The next prime is 18904211. The reversal of 18904172 is 27140981.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24797 + ... + 25547.

It is an arithmetic number, because the mean of its divisors is an integer number (842240).

Almost surely, 2^18904172 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18904172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20213760).

18904172 is an abundant number, since it is smaller than the sum of its proper divisors (21523348).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18904172 is a wasteful number, since it uses less digits than its factorization.

18904172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 822 (or 820 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 32.

The square root of 18904172 is about 4347.8928229661. The cubic root of 18904172 is about 266.3907987395.

The spelling of 18904172 in words is "eighteen million, nine hundred four thousand, one hundred seventy-two".