21820800000 has 264 divisors, whose sum is σ = 72727813872. Its totient is φ = 5816320000.

The previous prime is 21820799999. The next prime is 21820800017. The reversal of 21820800000 is 802812.

It is a super-2 number, since 2×21820800000² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21820800000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9598864 + ... + 9601136.

Almost surely, 2^21820800000 is an apocalyptic number.

21820800000 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 21820800000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36363906936).

21820800000 is an abundant number, since it is smaller than the sum of its proper divisors (50907013872).

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

21820800000 is an frugal number, since it uses more digits than its factorization.

21820800000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2321 (or 2283 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 21.

The spelling of 21820800000 in words is "twenty-one billion, eight hundred twenty million, eight hundred thousand".