18008172 has 144 divisors (see below), whose sum is σ = 58705920. Its totient is φ = 4523904.

The previous prime is 18008167. The next prime is 18008189. The reversal of 18008172 is 27180081.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 75229 + ... + 75467.

It is an arithmetic number, because the mean of its divisors is an integer number (407680).

Almost surely, 2^18008172 is an apocalyptic number.

18008172 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18008172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29352960).

18008172 is an abundant number, since it is smaller than the sum of its proper divisors (40697748).

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

18008172 is a wasteful number, since it uses less digits than its factorization.

18008172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292 (or 287 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

The square root of 18008172 is about 4243.6036572706. The cubic root of 18008172 is about 262.1137939735.

The spelling of 18008172 in words is "eighteen million, eight thousand, one hundred seventy-two".