21668548665512 has 384 divisors, whose sum is σ = 52529374540800. Its totient is φ = 8310517383168.

The previous prime is 21668548665481. The next prime is 21668548665541. The reversal of 21668548665512 is 21556684586612.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 32006718518 + ... + 32006719194.

It is an arithmetic number, because the mean of its divisors is an integer number (136795246200).

Almost surely, 2^{21668548665512} 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 21668548665512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26264687270400).

21668548665512 is an abundant number, since it is smaller than the sum of its proper divisors (30860825875288).

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

21668548665512 is a wasteful number, since it uses less digits than its factorization.

21668548665512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1673 (or 1662 counting only the distinct ones).

The product of its digits is 165888000, while the sum is 65.

The spelling of 21668548665512 in words is "twenty-one trillion, six hundred sixty-eight billion, five hundred forty-eight million, six hundred sixty-five thousand, five hundred twelve".