19664916 has 12 divisors (see below), whose sum is σ = 45884832. Its totient is φ = 6554968.

The previous prime is 19664899. The next prime is 19664923. The reversal of 19664916 is 61946691.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 819360 + ... + 819383.

It is an arithmetic number, because the mean of its divisors is an integer number (3823736).

Almost surely, 2^19664916 is an apocalyptic number.

It is an amenable number.

19664916 is an abundant number, since it is smaller than the sum of its proper divisors (26219916).

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

19664916 is a wasteful number, since it uses less digits than its factorization.

19664916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1638750 (or 1638748 counting only the distinct ones).

The product of its digits is 69984, while the sum is 42.

The square root of 19664916 is about 4434.5141785769. The cubic root of 19664916 is about 269.9172860488.

The spelling of 19664916 in words is "nineteen million, six hundred sixty-four thousand, nine hundred sixteen".