21631917404 has 24 divisors (see below), whose sum is σ = 39556823040. Its totient is φ = 10331279024.

The previous prime is 21631917383. The next prime is 21631917409. The reversal of 21631917404 is 40471913612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21631917409) 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, 97364 + ... + 229659.

It is an arithmetic number, because the mean of its divisors is an integer number (1648200960).

Almost surely, 2^21631917404 is an apocalyptic number.

It is an amenable number.

21631917404 is a deficient number, since it is larger than the sum of its proper divisors (17924905636).

21631917404 is a wasteful number, since it uses less digits than its factorization.

21631917404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327769 (or 327767 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 38.

The spelling of 21631917404 in words is "twenty-one billion, six hundred thirty-one million, nine hundred seventeen thousand, four hundred four".