21992890920 has 256 divisors, whose sum is σ = 88587233280. Its totient is φ = 4218393600.

The previous prime is 21992890919. The next prime is 21992890993. The reversal of 21992890920 is 2909829912.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 28575 + ... + 211665.

It is an arithmetic number, because the mean of its divisors is an integer number (346043880).

Almost surely, 2^21992890920 is an apocalyptic number.

21992890920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21992890920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44293616640).

21992890920 is an abundant number, since it is smaller than the sum of its proper divisors (66594342360).

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

21992890920 is a wasteful number, since it uses less digits than its factorization.

21992890920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183136 (or 183132 counting only the distinct ones).

The product of its (nonzero) digits is 419904, while the sum is 51.

The spelling of 21992890920 in words is "twenty-one billion, nine hundred ninety-two million, eight hundred ninety thousand, nine hundred twenty".