66766477 has 2 divisors, whose sum is σ = 66766478. Its totient is φ = 66766476.

The previous prime is 66766471. The next prime is 66766481. The reversal of 66766477 is 77466766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56340036 + 10426441 = 7506^2 + 3229^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66766477 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66766477.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66766471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33383238 + 33383239.

It is an arithmetic number, because the mean of its divisors is an integer number (33383239).

Almost surely, 2^66766477 is an apocalyptic number.

It is an amenable number.

66766477 is a deficient number, since it is larger than the sum of its proper divisors (1).

66766477 is an equidigital number, since it uses as much as digits as its factorization.

66766477 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1778112, while the sum is 49.

The square root of 66766477 is about 8171.0756329874. The cubic root of 66766477 is about 405.6823876725.

The spelling of 66766477 in words is "sixty-six million, seven hundred sixty-six thousand, four hundred seventy-seven".