18665808 has 80 divisors (see below), whose sum is σ = 55936896. Its totient is φ = 5253120.

The previous prime is 18665791. The next prime is 18665819. The reversal of 18665808 is 80856681.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 18665808.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24148 + ... + 24908.

Almost surely, 2^18665808 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 18665808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27968448).

18665808 is an abundant number, since it is smaller than the sum of its proper divisors (37271088).

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

18665808 is a wasteful number, since it uses less digits than its factorization.

18665808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 852 (or 846 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 42.

The square root of 18665808 is about 4320.3944264384. The cubic root of 18665808 is about 265.2664129834.

The spelling of 18665808 in words is "eighteen million, six hundred sixty-five thousand, eight hundred eight".