21389988360 has 64 divisors (see below), whose sum is σ = 69106121280. Its totient is φ = 5265227520.

The previous prime is 21389988329. The next prime is 21389988371. The reversal of 21389988360 is 6388998312.

It is a self number, because there is not a number n which added to its sum of digits gives 21389988360.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6854206 + ... + 6857325.

It is an arithmetic number, because the mean of its divisors is an integer number (1079783145).

Almost surely, 2^21389988360 is an apocalyptic number.

21389988360 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21389988360 is an abundant number, since it is smaller than the sum of its proper divisors (47716132920).

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

21389988360 is a wasteful number, since it uses less digits than its factorization.

21389988360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13711558 (or 13711554 counting only the distinct ones).

The product of its (nonzero) digits is 4478976, while the sum is 57.

The spelling of 21389988360 in words is "twenty-one billion, three hundred eighty-nine million, nine hundred eighty-eight thousand, three hundred sixty".