18521172 has 36 divisors (see below), whose sum is σ = 47197696. Its totient is φ = 6123600.

The previous prime is 18521161. The next prime is 18521179. The reversal of 18521172 is 27112581.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18521179) 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 11 ways as a sum of consecutive naturals, for example, 2547 + ... + 6597.

Almost surely, 2^18521172 is an apocalyptic number.

18521172 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

18521172 is an abundant number, since it is smaller than the sum of its proper divisors (28676524).

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

18521172 is a wasteful number, since it uses less digits than its factorization.

18521172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4188 (or 4183 counting only the distinct ones).

The product of its digits is 1120, while the sum is 27.

The square root of 18521172 is about 4303.6231247636. The cubic root of 18521172 is about 264.5794778091.

The spelling of 18521172 in words is "eighteen million, five hundred twenty-one thousand, one hundred seventy-two".