665811017 has 2 divisors, whose sum is σ = 665811018. Its totient is φ = 665811016.

The previous prime is 665810993. The next prime is 665811067. The reversal of 665811017 is 710118566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 544568896 + 121242121 = 23336^2 + 11011^2 .

It is a cyclic number.

It is not a de Polignac number, because 665811017 - 2⁶ = 665810953 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (665811067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332905508 + 332905509.

It is an arithmetic number, because the mean of its divisors is an integer number (332905509).

Almost surely, 2^665811017 is an apocalyptic number.

It is an amenable number.

665811017 is a deficient number, since it is larger than the sum of its proper divisors (1).

665811017 is an equidigital number, since it uses as much as digits as its factorization.

665811017 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 35.

The square root of 665811017 is about 25803.3140700957. The cubic root of 665811017 is about 873.2065653105.

The spelling of 665811017 in words is "six hundred sixty-five million, eight hundred eleven thousand, seventeen".