19918904 has 16 divisors (see below), whose sum is σ = 37588200. Its totient is φ = 9895392.

The previous prime is 19918901. The next prime is 19918909. The reversal of 19918904 is 40981991.

It is a super-2 number, since 2×19918904² = 793525473122432, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19918901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6674 + ... + 9185.

Almost surely, 2^19918904 is an apocalyptic number.

It is an amenable number.

19918904 is a deficient number, since it is larger than the sum of its proper divisors (17669296).

19918904 is a wasteful number, since it uses less digits than its factorization.

19918904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16022 (or 16018 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 41.

The square root of 19918904 is about 4463.0599368595. The cubic root of 19918904 is about 271.0743839784.

The spelling of 19918904 in words is "nineteen million, nine hundred eighteen thousand, nine hundred four".