21696994668128 has 48 divisors (see below), whose sum is σ = 46431724666320. Its totient is φ = 9920408756736.

The previous prime is 21696994668121. The next prime is 21696994668133. The reversal of 21696994668128 is 82186649969612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21696994668121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 243676223 + ... + 243765246.

It is an arithmetic number, because the mean of its divisors is an integer number (967327597215).

Almost surely, 2^{21696994668128} is an apocalyptic number.

It is an amenable number.

21696994668128 is an abundant number, since it is smaller than the sum of its proper divisors (24734729998192).

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

21696994668128 is a wasteful number, since it uses less digits than its factorization.

21696994668128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 487441599 (or 487441591 counting only the distinct ones).

The product of its digits is 967458816, while the sum is 77.

The spelling of 21696994668128 in words is "twenty-one trillion, six hundred ninety-six billion, nine hundred ninety-four million, six hundred sixty-eight thousand, one hundred twenty-eight".