66766916669 has 2 divisors, whose sum is σ = 66766916670. Its totient is φ = 66766916668.

The previous prime is 66766916647. The next prime is 66766916687. The reversal of 66766916669 is 96661966766.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45520356025 + 21246560644 = 213355^2 + 145762^2 .

It is a cyclic number.

It is not a de Polignac number, because 66766916669 - 2⁸ = 66766916413 is a prime.

It is a super-2 number, since 2×66766916669² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 66766916599 and 66766916608.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66766916569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33383458334 + 33383458335.

It is an arithmetic number, because the mean of its divisors is an integer number (33383458335).

Almost surely, 2^66766916669 is an apocalyptic number.

It is an amenable number.

66766916669 is a deficient number, since it is larger than the sum of its proper divisors (1).

66766916669 is an equidigital number, since it uses as much as digits as its factorization.

66766916669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 158723712, while the sum is 68.

The spelling of 66766916669 in words is "sixty-six billion, seven hundred sixty-six million, nine hundred sixteen thousand, six hundred sixty-nine".