18408720 has 160 divisors (see below), whose sum is σ = 65710080. Its totient is φ = 4216320.

The previous prime is 18408679. The next prime is 18408737. The reversal of 18408720 is 2780481.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 49977 + ... + 50343.

It is an arithmetic number, because the mean of its divisors is an integer number (410688).

Almost surely, 2^18408720 is an apocalyptic number.

18408720 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 18408720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32855040).

18408720 is an abundant number, since it is smaller than the sum of its proper divisors (47301360).

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

18408720 is a wasteful number, since it uses less digits than its factorization.

18408720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 413 (or 407 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 18408720 is about 4290.5384277501. The cubic root of 18408720 is about 264.0429223140.

The spelling of 18408720 in words is "eighteen million, four hundred eight thousand, seven hundred twenty".