21165615199 has 2 divisors, whose sum is σ = 21165615200. Its totient is φ = 21165615198.

The previous prime is 21165615181. The next prime is 21165615209. The reversal of 21165615199 is 99151656112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21165615199 - 2¹¹ = 21165613151 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21165612199) by changing a digit.

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 as a sum of consecutive naturals, namely, 10582807599 + 10582807600.

It is an arithmetic number, because the mean of its divisors is an integer number (10582807600).

Almost surely, 2^21165615199 is an apocalyptic number.

21165615199 is a deficient number, since it is larger than the sum of its proper divisors (1).

21165615199 is an equidigital number, since it uses as much as digits as its factorization.

21165615199 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145800, while the sum is 46.

The spelling of 21165615199 in words is "twenty-one billion, one hundred sixty-five million, six hundred fifteen thousand, one hundred ninety-nine".