21247798560768 has 576 divisors, whose sum is σ = 68514211584000. Its totient is φ = 6298757627904.

The previous prime is 21247798560701. The next prime is 21247798560817. The reversal of 21247798560768 is 86706589774212.

It is a happy number.

21247798560768 is a `hidden beast` number, since 2 + 1 + 2 + 4 + 7 + 7 + 9 + 8 + 5 + 607 + 6 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 21247798560696 and 21247798560705.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3495275553 + ... + 3495281631.

It is an arithmetic number, because the mean of its divisors is an integer number (118948284000).

Almost surely, 2^{21247798560768} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21247798560768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34257105792000).

21247798560768 is an abundant number, since it is smaller than the sum of its proper divisors (47266413023232).

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

21247798560768 is a wasteful number, since it uses less digits than its factorization.

21247798560768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6652 (or 6629 counting only the distinct ones).

The product of its (nonzero) digits is 568995840, while the sum is 72.

The spelling of 21247798560768 in words is "twenty-one trillion, two hundred forty-seven billion, seven hundred ninety-eight million, five hundred sixty thousand, seven hundred sixty-eight".