21317829672 has 32 divisors (see below), whose sum is σ = 54024641280. Its totient is φ = 7008600960.

The previous prime is 21317829667. The next prime is 21317829691. The reversal of 21317829672 is 27692871312.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6082104 + ... + 6085607.

It is an arithmetic number, because the mean of its divisors is an integer number (1688270040).

Almost surely, 2^21317829672 is an apocalyptic number.

It is an amenable number.

21317829672 is an abundant number, since it is smaller than the sum of its proper divisors (32706811608).

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

21317829672 is a wasteful number, since it uses less digits than its factorization.

21317829672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12167793 (or 12167789 counting only the distinct ones).

The product of its digits is 508032, while the sum is 48.

The spelling of 21317829672 in words is "twenty-one billion, three hundred seventeen million, eight hundred twenty-nine thousand, six hundred seventy-two".