21161524804 has 12 divisors (see below), whose sum is σ = 42323049664. Its totient is φ = 9069224904.

The previous prime is 21161524781. The next prime is 21161524829. The reversal of 21161524804 is 40842516112.

21161524804 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 21161524804.

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, 377884344 + ... + 377884399.

Almost surely, 2^21161524804 is an apocalyptic number.

It is an amenable number.

21161524804 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21161524804 is a wasteful number, since it uses less digits than its factorization.

21161524804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 755768754 (or 755768752 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 34.

The spelling of 21161524804 in words is "twenty-one billion, one hundred sixty-one million, five hundred twenty-four thousand, eight hundred four".