21664089360 has 80 divisors (see below), whose sum is σ = 74620759680. Its totient is φ = 5777089920.

The previous prime is 21664089329. The next prime is 21664089361. The reversal of 21664089360 is 6398046612.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (21664089361) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5012676 + ... + 5016995.

It is an arithmetic number, because the mean of its divisors is an integer number (932759496).

Almost surely, 2^21664089360 is an apocalyptic number.

21664089360 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21664089360 is an abundant number, since it is smaller than the sum of its proper divisors (52956670320).

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

21664089360 is a wasteful number, since it uses less digits than its factorization.

21664089360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10029693 (or 10029681 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The spelling of 21664089360 in words is "twenty-one billion, six hundred sixty-four million, eighty-nine thousand, three hundred sixty".