66766673 has 2 divisors, whose sum is σ = 66766674. Its totient is φ = 66766672.

The previous prime is 66766669. The next prime is 66766681. The reversal of 66766673 is 37666766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39225169 + 27541504 = 6263^2 + 5248^2 .

It is a cyclic number.

It is not a de Polignac number, because 66766673 - 2² = 66766669 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (66766663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33383336 + 33383337.

It is an arithmetic number, because the mean of its divisors is an integer number (33383337).

Almost surely, 2^66766673 is an apocalyptic number.

It is an amenable number.

66766673 is a deficient number, since it is larger than the sum of its proper divisors (1).

66766673 is an equidigital number, since it uses as much as digits as its factorization.

66766673 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1143072, while the sum is 47.

The square root of 66766673 is about 8171.0876265036. The cubic root of 66766673 is about 405.6827846465.

The spelling of 66766673 in words is "sixty-six million, seven hundred sixty-six thousand, six hundred seventy-three".