21517768848160 has 48 divisors (see below), whose sum is σ = 54746169593976. Its totient is φ = 7945022343168.

The previous prime is 21517768848139. The next prime is 21517768848193. The reversal of 21517768848160 is 6184886771512.

It can be written as a sum of positive squares in 4 ways, for example, as 9068698599184 + 12449070248976 = 3011428^2 + 3528324^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21517768848092 and 21517768848101.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5172538509 + ... + 5172542668.

Almost surely, 2^{21517768848160} is an apocalyptic number.

21517768848160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21517768848160 is an abundant number, since it is smaller than the sum of its proper divisors (33228400745816).

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

21517768848160 is a wasteful number, since it uses less digits than its factorization.

21517768848160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10345081205 (or 10345081197 counting only the distinct ones).

The product of its (nonzero) digits is 36126720, while the sum is 64.

The spelling of 21517768848160 in words is "twenty-one trillion, five hundred seventeen billion, seven hundred sixty-eight million, eight hundred forty-eight thousand, one hundred sixty".