21992065920 has 1024 divisors, whose sum is σ = 90419328000. Its totient is φ = 5003182080.

The previous prime is 21992065919. The next prime is 21992065951. The reversal of 21992065920 is 2956029912.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 372746851 + ... + 372746909.

It is an arithmetic number, because the mean of its divisors is an integer number (88300125).

Almost surely, 2^21992065920 is an apocalyptic number.

21992065920 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 21992065920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45209664000).

21992065920 is an abundant number, since it is smaller than the sum of its proper divisors (68427262080).

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

21992065920 is a wasteful number, since it uses less digits than its factorization.

21992065920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188 (or 170 counting only the distinct ones).

The product of its (nonzero) digits is 174960, while the sum is 45.

The spelling of 21992065920 in words is "twenty-one billion, nine hundred ninety-two million, sixty-five thousand, nine hundred twenty".