66321779 has 2 divisors, whose sum is σ = 66321780. Its totient is φ = 66321778.

The previous prime is 66321769. The next prime is 66321793. The reversal of 66321779 is 97712366.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66321779 - 2²⁰ = 65273203 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (66321769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33160889 + 33160890.

It is an arithmetic number, because the mean of its divisors is an integer number (33160890).

Almost surely, 2^66321779 is an apocalyptic number.

66321779 is a deficient number, since it is larger than the sum of its proper divisors (1).

66321779 is an equidigital number, since it uses as much as digits as its factorization.

66321779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 95256, while the sum is 41.

The square root of 66321779 is about 8143.8184532810. The cubic root of 66321779 is about 404.7796983047.

The spelling of 66321779 in words is "sixty-six million, three hundred twenty-one thousand, seven hundred seventy-nine".