66991116659 has 2 divisors, whose sum is σ = 66991116660. Its totient is φ = 66991116658.

The previous prime is 66991116641. The next prime is 66991116679. The reversal of 66991116659 is 95661119966.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66991116659 is a prime.

It is a super-2 number, since 2×66991116659² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66991116598 and 66991116607.

It is not a weakly prime, because it can be changed into another prime (66991116679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33495558329 + 33495558330.

It is an arithmetic number, because the mean of its divisors is an integer number (33495558330).

Almost surely, 2^66991116659 is an apocalyptic number.

66991116659 is a deficient number, since it is larger than the sum of its proper divisors (1).

66991116659 is an equidigital number, since it uses as much as digits as its factorization.

66991116659 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4723920, while the sum is 59.

The spelling of 66991116659 in words is "sixty-six billion, nine hundred ninety-one million, one hundred sixteen thousand, six hundred fifty-nine".