21520394681160 has 512 divisors, whose sum is σ = 74273863680000. Its totient is φ = 4953544409088.

The previous prime is 21520394681017. The next prime is 21520394681161. The reversal of 21520394681160 is 6118649302512.

It is not an unprimeable number, because it can be changed into a prime (21520394681161) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 285352177 + ... + 285427583.

It is an arithmetic number, because the mean of its divisors is an integer number (145066140000).

Almost surely, 2^{21520394681160} is an apocalyptic number.

21520394681160 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 21520394681160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37136931840000).

21520394681160 is an abundant number, since it is smaller than the sum of its proper divisors (52753468998840).

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

21520394681160 is a wasteful number, since it uses less digits than its factorization.

21520394681160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75693 (or 75689 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 48.

The spelling of 21520394681160 in words is "twenty-one trillion, five hundred twenty billion, three hundred ninety-four million, six hundred eighty-one thousand, one hundred sixty".