66766677666791 has 2 divisors, whose sum is σ = 66766677666792. Its totient is φ = 66766677666790.

The previous prime is 66766677666763. The next prime is 66766677666841. The reversal of 66766677666791 is 19766677666766.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66766677666791 is a prime.

It is a super-3 number, since 3×66766677666791³ (a number of 42 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

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 (66766677666761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33383338833395 + 33383338833396.

It is an arithmetic number, because the mean of its divisors is an integer number (33383338833396).

Almost surely, 2^{66766677666791} is an apocalyptic number.

66766677666791 is a deficient number, since it is larger than the sum of its proper divisors (1).

66766677666791 is an equidigital number, since it uses as much as digits as its factorization.

66766677666791 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36294822144, while the sum is 86.

The spelling of 66766677666791 in words is "sixty-six trillion, seven hundred sixty-six billion, six hundred seventy-seven million, six hundred sixty-six thousand, seven hundred ninety-one".