18447872 has 40 divisors (see below), whose sum is σ = 37269936. Its totient is φ = 9121792.

The previous prime is 18447833. The next prime is 18447887. The reversal of 18447872 is 27874481.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70013 + ... + 70275.

Almost surely, 2^18447872 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 18447872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18634968).

18447872 is an abundant number, since it is smaller than the sum of its proper divisors (18822064).

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

18447872 is an equidigital number, since it uses as much as digits as its factorization.

18447872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418 (or 402 counting only the distinct ones).

The product of its digits is 100352, while the sum is 41.

The square root of 18447872 is about 4295.0986018950. The cubic root of 18447872 is about 264.2299801914.

The spelling of 18447872 in words is "eighteen million, four hundred forty-seven thousand, eight hundred seventy-two".