18999808 has 40 divisors (see below), whose sum is σ = 38890368. Its totient is φ = 9268224.

The previous prime is 18999787. The next prime is 18999821. The reversal of 18999808 is 80899981.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21585 + ... + 22447.

Almost surely, 2^18999808 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 18999808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19445184).

18999808 is an abundant number, since it is smaller than the sum of its proper divisors (19890560).

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

18999808 is an frugal number, since it uses more digits than its factorization.

18999808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 924 (or 908 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 52.

The square root of 18999808 is about 4358.8769195746. The cubic root of 18999808 is about 266.8392660391.

The spelling of 18999808 in words is "eighteen million, nine hundred ninety-nine thousand, eight hundred eight".