21684982072 has 16 divisors (see below), whose sum is σ = 43786983240. Its totient is φ = 10008453216.

The previous prime is 21684982069. The next prime is 21684982181. The reversal of 21684982072 is 27028948612.

It is a super-2 number, since 2×21684982072² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104254618 + ... + 104254825.

Almost surely, 2^21684982072 is an apocalyptic number.

It is an amenable number.

21684982072 is an abundant number, since it is smaller than the sum of its proper divisors (22102001168).

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

21684982072 is a wasteful number, since it uses less digits than its factorization.

21684982072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208509462 (or 208509458 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 49.

The spelling of 21684982072 in words is "twenty-one billion, six hundred eighty-four million, nine hundred eighty-two thousand, seventy-two".