66511672699991 has 2 divisors, whose sum is σ = 66511672699992. Its totient is φ = 66511672699990.

The previous prime is 66511672699883. The next prime is 66511672700059. The reversal of 66511672699991 is 19999627611566.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66511672699991 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66511674699991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33255836349995 + 33255836349996.

It is an arithmetic number, because the mean of its divisors is an integer number (33255836349996).

Almost surely, 2^{66511672699991} is an apocalyptic number.

66511672699991 is a deficient number, since it is larger than the sum of its proper divisors (1).

66511672699991 is an equidigital number, since it uses as much as digits as its factorization.

66511672699991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 595213920, while the sum is 77.

The spelling of 66511672699991 in words is "sixty-six trillion, five hundred eleven billion, six hundred seventy-two million, six hundred ninety-nine thousand, nine hundred ninety-one".