21201808924 has 12 divisors (see below), whose sum is σ = 37148036184. Its totient is φ = 10588084304.

The previous prime is 21201808913. The next prime is 21201808987. The reversal of 21201808924 is 42980810212.

It is a happy number.

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, 3201319 + ... + 3207934.

It is an arithmetic number, because the mean of its divisors is an integer number (3095669682).

Almost surely, 2^21201808924 is an apocalyptic number.

It is an amenable number.

21201808924 is a deficient number, since it is larger than the sum of its proper divisors (15946227260).

21201808924 is a wasteful number, since it uses less digits than its factorization.

21201808924 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6410084 (or 6410082 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 37.

The spelling of 21201808924 in words is "twenty-one billion, two hundred one million, eight hundred eight thousand, nine hundred twenty-four".