21636843792 has 40 divisors (see below), whose sum is σ = 56101468800. Its totient is φ = 7185663360.

The previous prime is 21636843779. The next prime is 21636843803. The reversal of 21636843792 is 29734863612.

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, 818667 + ... + 844682.

It is an arithmetic number, because the mean of its divisors is an integer number (1402536720).

Almost surely, 2^21636843792 is an apocalyptic number.

It is an amenable number.

21636843792 is an abundant number, since it is smaller than the sum of its proper divisors (34464625008).

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

21636843792 is a wasteful number, since it uses less digits than its factorization.

21636843792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1663631 (or 1663625 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 51.

The spelling of 21636843792 in words is "twenty-one billion, six hundred thirty-six million, eight hundred forty-three thousand, seven hundred ninety-two".