19990808 has 8 divisors (see below), whose sum is σ = 37482780. Its totient is φ = 9995400.

The previous prime is 19990801. The next prime is 19990811. The reversal of 19990808 is 80809991.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19990801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1249418 + ... + 1249433.

Almost surely, 2^19990808 is an apocalyptic number.

It is an amenable number.

19990808 is a deficient number, since it is larger than the sum of its proper divisors (17491972).

19990808 is a wasteful number, since it uses less digits than its factorization.

19990808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2498857 (or 2498853 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 44.

The square root of 19990808 is about 4471.1081400476. The cubic root of 19990808 is about 271.4001704092.

The spelling of 19990808 in words is "nineteen million, nine hundred ninety thousand, eight hundred eight".