18409664 has 112 divisors (see below), whose sum is σ = 46939200. Its totient is φ = 6967296.

The previous prime is 18409639. The next prime is 18409669. The reversal of 18409664 is 46690481.

It is a tau number, because it is divible by the number of its divisors (112).

It is not an unprimeable number, because it can be changed into a prime (18409669) 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, 168842 + ... + 168950.

It is an arithmetic number, because the mean of its divisors is an integer number (419100).

Almost surely, 2^18409664 is an apocalyptic number.

18409664 is a gapful number since it is divisible by the number (14) 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 18409664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23469600).

18409664 is an abundant number, since it is smaller than the sum of its proper divisors (28529536).

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

18409664 is a wasteful number, since it uses less digits than its factorization.

18409664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170 (or 160 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 18409664 is about 4290.6484358428. The cubic root of 18409664 is about 264.0474356146.

The spelling of 18409664 in words is "eighteen million, four hundred nine thousand, six hundred sixty-four".