21720598448640 has 1920 divisors, whose sum is σ = 90206986383360. Its totient is φ = 4416188055552.

The previous prime is 21720598448621. The next prime is 21720598448651. The reversal of 21720598448640 is 4684489502712.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (1920).

It is a Harshad number since it is a multiple of its sum of digits (60).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 16618666867 + ... + 16618668173.

It is an arithmetic number, because the mean of its divisors is an integer number (46982805408).

Almost surely, 2^{21720598448640} is an apocalyptic number.

21720598448640 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 21720598448640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45103493191680).

21720598448640 is an abundant number, since it is smaller than the sum of its proper divisors (68486387934720).

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

21720598448640 is a wasteful number, since it uses less digits than its factorization.

21720598448640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1482 (or 1459 counting only the distinct ones).

The product of its (nonzero) digits is 30965760, while the sum is 60.

The spelling of 21720598448640 in words is "twenty-one trillion, seven hundred twenty billion, five hundred ninety-eight million, four hundred forty-eight thousand, six hundred forty".