18099172 has 48 divisors (see below), whose sum is σ = 41050240. Its totient is φ = 6780672.

The previous prime is 18099167. The next prime is 18099199. The reversal of 18099172 is 27199081.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 5608 + ... + 8224.

Almost surely, 2^18099172 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 18099172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20525120).

18099172 is an abundant number, since it is smaller than the sum of its proper divisors (22951068).

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

18099172 is a wasteful number, since it uses less digits than its factorization.

18099172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2660 (or 2658 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 18099172 is about 4254.3121653212. The cubic root of 18099172 is about 262.5545622031.

Subtracting 18099172 from its reverse (27199081), we obtain a palindrome (9099909).

The spelling of 18099172 in words is "eighteen million, ninety-nine thousand, one hundred seventy-two".