21804172636 has 12 divisors (see below), whose sum is σ = 38385790128. Its totient is φ = 10836804032.

The previous prime is 21804172619. The next prime is 21804172699. The reversal of 21804172636 is 63627140812.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16319821 + ... + 16321156.

It is an arithmetic number, because the mean of its divisors is an integer number (3198815844).

Almost surely, 2^21804172636 is an apocalyptic number.

It is an amenable number.

21804172636 is a deficient number, since it is larger than the sum of its proper divisors (16581617492).

21804172636 is a wasteful number, since it uses less digits than its factorization.

21804172636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32641148 (or 32641146 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 40.

The spelling of 21804172636 in words is "twenty-one billion, eight hundred four million, one hundred seventy-two thousand, six hundred thirty-six".