19916664 has 32 divisors (see below), whose sum is σ = 49938000. Its totient is φ = 6619392.

The previous prime is 19916657. The next prime is 19916669. The reversal of 19916664 is 46661991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19916669) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8802 + ... + 10830.

Almost surely, 2^19916664 is an apocalyptic number.

It is an amenable number.

19916664 is an abundant number, since it is smaller than the sum of its proper divisors (30021336).

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

19916664 is a wasteful number, since it uses less digits than its factorization.

19916664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2447 (or 2443 counting only the distinct ones).

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

The square root of 19916664 is about 4462.8089808998. The cubic root of 19916664 is about 271.0642222851.

The spelling of 19916664 in words is "nineteen million, nine hundred sixteen thousand, six hundred sixty-four".