66558773 has 2 divisors, whose sum is σ = 66558774. Its totient is φ = 66558772.

The previous prime is 66558769. The next prime is 66558787. The reversal of 66558773 is 37785566.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64915249 + 1643524 = 8057^2 + 1282^2 .

It is a cyclic number.

It is not a de Polignac number, because 66558773 - 2² = 66558769 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66558733) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33279386 + 33279387.

It is an arithmetic number, because the mean of its divisors is an integer number (33279387).

Almost surely, 2^66558773 is an apocalyptic number.

It is an amenable number.

66558773 is a deficient number, since it is larger than the sum of its proper divisors (1).

66558773 is an equidigital number, since it uses as much as digits as its factorization.

66558773 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1058400, while the sum is 47.

The square root of 66558773 is about 8158.3560231213. The cubic root of 66558773 is about 405.2612712351.

The spelling of 66558773 in words is "sixty-six million, five hundred fifty-eight thousand, seven hundred seventy-three".