66991116679 has 2 divisors, whose sum is σ = 66991116680. Its totient is φ = 66991116678.

The previous prime is 66991116659. The next prime is 66991116707. The reversal of 66991116679 is 97661119966.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66991116679 - 2¹⁵ = 66991083911 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66991116659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33495558339 + 33495558340.

It is an arithmetic number, because the mean of its divisors is an integer number (33495558340).

Almost surely, 2^66991116679 is an apocalyptic number.

66991116679 is a deficient number, since it is larger than the sum of its proper divisors (1).

66991116679 is an equidigital number, since it uses as much as digits as its factorization.

66991116679 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6613488, while the sum is 61.

The spelling of 66991116679 in words is "sixty-six billion, nine hundred ninety-one million, one hundred sixteen thousand, six hundred seventy-nine".