16564106235991 has 2 divisors, whose sum is σ = 16564106235992. Its totient is φ = 16564106235990.

The previous prime is 16564106235979. The next prime is 16564106236019. The reversal of 16564106235991 is 19953260146561.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 16564106235991 - 2¹⁷ = 16564106104919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16564106235191) 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, 8282053117995 + 8282053117996.

It is an arithmetic number, because the mean of its divisors is an integer number (8282053117996).

Almost surely, 2^{16564106235991} is an apocalyptic number.

16564106235991 is a deficient number, since it is larger than the sum of its proper divisors (1).

16564106235991 is an equidigital number, since it uses as much as digits as its factorization.

16564106235991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10497600, while the sum is 58.

The spelling of 16564106235991 in words is "sixteen trillion, five hundred sixty-four billion, one hundred six million, two hundred thirty-five thousand, nine hundred ninety-one".