18166720 has 112 divisors (see below), whose sum is σ = 50950368. Its totient is φ = 6082560.

The previous prime is 18166697. The next prime is 18166721. The reversal of 18166720 is 2766181.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18166721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45562 + ... + 45958.

It is an arithmetic number, because the mean of its divisors is an integer number (454914).

Almost surely, 2^18166720 is an apocalyptic number.

18166720 is a gapful number since it is divisible by the number (10) 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 18166720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25475184).

18166720 is an abundant number, since it is smaller than the sum of its proper divisors (32783648).

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

18166720 is a wasteful number, since it uses less digits than its factorization.

18166720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438 (or 428 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 18166720 is about 4262.2435406720. The cubic root of 18166720 is about 262.8807837230.

The spelling of 18166720 in words is "eighteen million, one hundred sixty-six thousand, seven hundred twenty".