21056116099 has 2 divisors, whose sum is σ = 21056116100. Its totient is φ = 21056116098.

The previous prime is 21056116079. The next prime is 21056116129. The reversal of 21056116099 is 99061165012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21056116099 - 2¹⁹ = 21055591811 is a prime.

It is not a weakly prime, because it can be changed into another prime (21056116049) by changing a digit.

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 as a sum of consecutive naturals, namely, 10528058049 + 10528058050.

It is an arithmetic number, because the mean of its divisors is an integer number (10528058050).

Almost surely, 2^21056116099 is an apocalyptic number.

21056116099 is a deficient number, since it is larger than the sum of its proper divisors (1).

21056116099 is an equidigital number, since it uses as much as digits as its factorization.

21056116099 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 29160, while the sum is 40.

The spelling of 21056116099 in words is "twenty-one billion, fifty-six million, one hundred sixteen thousand, ninety-nine".