66780773 has 2 divisors, whose sum is σ = 66780774. Its totient is φ = 66780772.

The previous prime is 66780767. The next prime is 66780793. The reversal of 66780773 is 37708766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54656449 + 12124324 = 7393^2 + 3482^2 .

It is a cyclic number.

It is not a de Polignac number, because 66780773 - 2¹⁰ = 66779749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66780793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33390386 + 33390387.

It is an arithmetic number, because the mean of its divisors is an integer number (33390387).

Almost surely, 2^66780773 is an apocalyptic number.

It is an amenable number.

66780773 is a deficient number, since it is larger than the sum of its proper divisors (1).

66780773 is an equidigital number, since it uses as much as digits as its factorization.

66780773 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 296352, while the sum is 44.

The square root of 66780773 is about 8171.9503791935. The cubic root of 66780773 is about 405.7113404333.

The spelling of 66780773 in words is "sixty-six million, seven hundred eighty thousand, seven hundred seventy-three".