19990904 has 16 divisors (see below), whose sum is σ = 37997520. Its totient is φ = 9858240.

The previous prime is 19990897. The next prime is 19990931. The reversal of 19990904 is 40909991.

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, 16532 + ... + 17699.

It is an arithmetic number, because the mean of its divisors is an integer number (2374845).

Almost surely, 2^19990904 is an apocalyptic number.

It is an amenable number.

19990904 is a deficient number, since it is larger than the sum of its proper divisors (18006616).

19990904 is a wasteful number, since it uses less digits than its factorization.

19990904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34310 (or 34306 counting only the distinct ones).

The product of its (nonzero) digits is 26244, while the sum is 41.

The square root of 19990904 is about 4471.1188756283. The cubic root of 19990904 is about 271.4006048484.

The spelling of 19990904 in words is "nineteen million, nine hundred ninety thousand, nine hundred four".