18408864 has 48 divisors (see below), whose sum is σ = 48589632. Its totient is φ = 6102528.

The previous prime is 18408847. The next prime is 18408883. The reversal of 18408864 is 46880481.

It is a tau number, because it is divible by the number of its divisors (48).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21957 + ... + 22779.

It is an arithmetic number, because the mean of its divisors is an integer number (1012284).

Almost surely, 2^18408864 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 18408864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24294816).

18408864 is an abundant number, since it is smaller than the sum of its proper divisors (30180768).

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

18408864 is a wasteful number, since it uses less digits than its factorization.

18408864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1069 (or 1061 counting only the distinct ones).

The product of its (nonzero) digits is 49152, while the sum is 39.

The square root of 18408864 is about 4290.5552088279. Note that the first 3 decimals coincide. The cubic root of 18408864 is about 264.0436107936.

The spelling of 18408864 in words is "eighteen million, four hundred eight thousand, eight hundred sixty-four".