18664977688 has 96 divisors (see below), whose sum is σ = 43165256400. Its totient is φ = 7518271488.

The previous prime is 18664977649. The next prime is 18664977691. The reversal of 18664977688 is 88677946681.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6349323 + ... + 6352261.

Almost surely, 2^18664977688 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 18664977688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21582628200).

18664977688 is an abundant number, since it is smaller than the sum of its proper divisors (24500278712).

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

18664977688 is a wasteful number, since it uses less digits than its factorization.

18664977688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3929 (or 3918 counting only the distinct ones).

The product of its digits is 195084288, while the sum is 70.

The spelling of 18664977688 in words is "eighteen billion, six hundred sixty-four million, nine hundred seventy-seven thousand, six hundred eighty-eight".