21913824920 has 32 divisors (see below), whose sum is σ = 53098884720. Its totient is φ = 8091258240.

The previous prime is 21913824917. The next prime is 21913824929. The reversal of 21913824920 is 2942831912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21913824929) 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, 21070466 + ... + 21071505.

Almost surely, 2^21913824920 is an apocalyptic number.

21913824920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21913824920 is an abundant number, since it is smaller than the sum of its proper divisors (31185059800).

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

21913824920 is a wasteful number, since it uses less digits than its factorization.

21913824920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42141995 (or 42141991 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 41.

The spelling of 21913824920 in words is "twenty-one billion, nine hundred thirteen million, eight hundred twenty-four thousand, nine hundred twenty".