18199808 has 72 divisors (see below), whose sum is σ = 41501376. Its totient is φ = 7884800.

The previous prime is 18199801. The next prime is 18199823. The reversal of 18199808 is 80899181.

It is a happy number.

It is a super-2 number, since 2×18199808² = 662466022473728, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18199801) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64628 + ... + 64908.

It is an arithmetic number, because the mean of its divisors is an integer number (576408).

Almost surely, 2^18199808 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 18199808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20750688).

18199808 is an abundant number, since it is smaller than the sum of its proper divisors (23301568).

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

18199808 is a wasteful number, since it uses less digits than its factorization.

18199808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331 (or 317 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 44.

The square root of 18199808 is about 4266.1232987339. The cubic root of 18199808 is about 263.0402864452.

The spelling of 18199808 in words is "eighteen million, one hundred ninety-nine thousand, eight hundred eight".