66736736736991 has 2 divisors, whose sum is σ = 66736736736992. Its totient is φ = 66736736736990.

The previous prime is 66736736736977. The next prime is 66736736737067. The reversal of 66736736736991 is 19963763763766.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66736736736991 - 2⁷ = 66736736736863 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66736736736491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33368368368495 + 33368368368496.

It is an arithmetic number, because the mean of its divisors is an integer number (33368368368496).

Almost surely, 2^{66736736736991} is an apocalyptic number.

66736736736991 is a deficient number, since it is larger than the sum of its proper divisors (1).

66736736736991 is an equidigital number, since it uses as much as digits as its factorization.

66736736736991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5833096416, while the sum is 79.

The spelling of 66736736736991 in words is "sixty-six trillion, seven hundred thirty-six billion, seven hundred thirty-six million, seven hundred thirty-six thousand, nine hundred ninety-one".