21637632959 has 8 divisors (see below), whose sum is σ = 21985592832. Its totient is φ = 21291751000.

The previous prime is 21637632899. The next prime is 21637633013. The reversal of 21637632959 is 95923673612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21637632959 - 2²⁴ = 21620855743 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21637632959.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21637632659) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 498479 + ... + 540144.

It is an arithmetic number, because the mean of its divisors is an integer number (2748199104).

Almost surely, 2^21637632959 is an apocalyptic number.

21637632959 is a deficient number, since it is larger than the sum of its proper divisors (347959873).

21637632959 is a wasteful number, since it uses less digits than its factorization.

21637632959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1038957.

The product of its digits is 3674160, while the sum is 53.

The spelling of 21637632959 in words is "twenty-one billion, six hundred thirty-seven million, six hundred thirty-two thousand, nine hundred fifty-nine".