21680318364 has 24 divisors (see below), whose sum is σ = 50827166208. Its totient is φ = 7192521840.

The previous prime is 21680318329. The next prime is 21680318371. The reversal of 21680318364 is 46381308612.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4278732 + ... + 4283795.

It is an arithmetic number, because the mean of its divisors is an integer number (2117798592).

Almost surely, 2^21680318364 is an apocalyptic number.

It is an amenable number.

21680318364 is an abundant number, since it is smaller than the sum of its proper divisors (29146847844).

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

21680318364 is a wasteful number, since it uses less digits than its factorization.

21680318364 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8562745 (or 8562743 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 42.

The spelling of 21680318364 in words is "twenty-one billion, six hundred eighty million, three hundred eighteen thousand, three hundred sixty-four".