18999904 has 72 divisors (see below), whose sum is σ = 47056464. Its totient is φ = 7392000.

The previous prime is 18999889. The next prime is 18999913. The reversal of 18999904 is 40999981.

It is a super-3 number, since 3×18999904³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26754 + ... + 27454.

It is an arithmetic number, because the mean of its divisors is an integer number (653562).

Almost surely, 2^18999904 is an apocalyptic number.

18999904 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 18999904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23528232).

18999904 is an abundant number, since it is smaller than the sum of its proper divisors (28056560).

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

18999904 is a wasteful number, since it uses less digits than its factorization.

18999904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 740 (or 721 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 49.

The square root of 18999904 is about 4358.8879315715. The cubic root of 18999904 is about 266.8397154564.

The spelling of 18999904 in words is "eighteen million, nine hundred ninety-nine thousand, nine hundred four".