21785988000 has 768 divisors, whose sum is σ = 85542912000. Its totient is φ = 4843238400.

The previous prime is 21785987999. The next prime is 21785988011. The reversal of 21785988000 is 88958712.

It is a super-2 number, since 2×21785988000² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

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, 275771961 + ... + 275772039.

It is an arithmetic number, because the mean of its divisors is an integer number (111384000).

Almost surely, 2^21785988000 is an apocalyptic number.

21785988000 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 21785988000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42771456000).

21785988000 is an abundant number, since it is smaller than the sum of its proper divisors (63756924000).

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

21785988000 is an equidigital number, since it uses as much as digits as its factorization.

21785988000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195 (or 163 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 48.

The spelling of 21785988000 in words is "twenty-one billion, seven hundred eighty-five million, nine hundred eighty-eight thousand".