18331984 has 60 divisors (see below), whose sum is σ = 41411412. Its totient is φ = 7828480.

The previous prime is 18331981. The next prime is 18331993. The reversal of 18331984 is 48913381.

It can be written as a sum of positive squares in 2 ways, for example, as 7441984 + 10890000 = 2728^2 + 3300^2 .

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18331981) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 32634 + ... + 33190.

Almost surely, 2^18331984 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 18331984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20705706).

18331984 is an abundant number, since it is smaller than the sum of its proper divisors (23079428).

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

18331984 is a wasteful number, since it uses less digits than its factorization.

18331984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 604 (or 587 counting only the distinct ones).

The product of its digits is 20736, while the sum is 37.

The square root of 18331984 is about 4281.5866218027. The cubic root of 18331984 is about 263.6755272918.

The spelling of 18331984 in words is "eighteen million, three hundred thirty-one thousand, nine hundred eighty-four".