21664982276 has 48 divisors (see below), whose sum is σ = 44761608192. Its totient is φ = 8978666400.

The previous prime is 21664982249. The next prime is 21664982293. The reversal of 21664982276 is 67228946612.

It is a happy number.

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, 1229891 + ... + 1247381.

It is an arithmetic number, because the mean of its divisors is an integer number (932533504).

Almost surely, 2^21664982276 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 21664982276, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22380804096).

21664982276 is an abundant number, since it is smaller than the sum of its proper divisors (23096625916).

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

21664982276 is a wasteful number, since it uses less digits than its factorization.

21664982276 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18960 (or 18958 counting only the distinct ones).

The product of its digits is 3483648, while the sum is 53.

The spelling of 21664982276 in words is "twenty-one billion, six hundred sixty-four million, nine hundred eighty-two thousand, two hundred seventy-six".