19808664 has 16 divisors (see below), whose sum is σ = 49521720. Its totient is φ = 6602880.

The previous prime is 19808647. The next prime is 19808683. The reversal of 19808664 is 46680891.

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, 412657 + ... + 412704.

Almost surely, 2^19808664 is an apocalyptic number.

It is an amenable number.

19808664 is an abundant number, since it is smaller than the sum of its proper divisors (29713056).

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

19808664 is a wasteful number, since it uses less digits than its factorization.

19808664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 825370 (or 825366 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 42.

The square root of 19808664 is about 4450.6925303822. The cubic root of 19808664 is about 270.5733768408.

The spelling of 19808664 in words is "nineteen million, eight hundred eight thousand, six hundred sixty-four".