21669964728679 has 2 divisors, whose sum is σ = 21669964728680. Its totient is φ = 21669964728678.

The previous prime is 21669964728553. The next prime is 21669964728739. The reversal of 21669964728679 is 97682746996612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21669964728679 - 2²⁵ = 21669931174247 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21669964725679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10834982364339 + 10834982364340.

It is an arithmetic number, because the mean of its divisors is an integer number (10834982364340).

Almost surely, 2^{21669964728679} is an apocalyptic number.

21669964728679 is a deficient number, since it is larger than the sum of its proper divisors (1).

21669964728679 is an equidigital number, since it uses as much as digits as its factorization.

21669964728679 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5925685248, while the sum is 82.

The spelling of 21669964728679 in words is "twenty-one trillion, six hundred sixty-nine billion, nine hundred sixty-four million, seven hundred twenty-eight thousand, six hundred seventy-nine".