665718861757 has 2 divisors, whose sum is σ = 665718861758. Its totient is φ = 665718861756.

The previous prime is 665718861733. The next prime is 665718861761. The reversal of 665718861757 is 757168817566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 401475571641 + 264243290116 = 633621^2 + 514046^2 .

It is a cyclic number.

It is not a de Polignac number, because 665718861757 - 2¹¹ = 665718859709 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 665718861692 and 665718861701.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665718867757) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332859430878 + 332859430879.

It is an arithmetic number, because the mean of its divisors is an integer number (332859430879).

Almost surely, 2^665718861757 is an apocalyptic number.

It is an amenable number.

665718861757 is a deficient number, since it is larger than the sum of its proper divisors (1).

665718861757 is an equidigital number, since it uses as much as digits as its factorization.

665718861757 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 118540800, while the sum is 67.

The spelling of 665718861757 in words is "six hundred sixty-five billion, seven hundred eighteen million, eight hundred sixty-one thousand, seven hundred fifty-seven".