19889664 has 80 divisors (see below), whose sum is σ = 55389312. Its totient is φ = 6330368.

The previous prime is 19889663. The next prime is 19889689. The reversal of 19889664 is 46698891.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19889663) 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, 35047 + ... + 35609.

Almost surely, 2^19889664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19889664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27694656).

19889664 is an abundant number, since it is smaller than the sum of its proper divisors (35499648).

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

19889664 is an equidigital number, since it uses as much as digits as its factorization.

19889664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 607 (or 591 counting only the distinct ones).

The product of its digits is 746496, while the sum is 51.

The square root of 19889664 is about 4459.7829543600. The cubic root of 19889664 is about 270.9416776041.

The spelling of 19889664 in words is "nineteen million, eight hundred eighty-nine thousand, six hundred sixty-four".