665365563517 has 2 divisors, whose sum is σ = 665365563518. Its totient is φ = 665365563516.

The previous prime is 665365563493. The next prime is 665365563659. The reversal of 665365563517 is 715365563566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 661260086041 + 4105477476 = 813179^2 + 64074^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665365563517 is a prime.

It is a super-2 number, since 2×665365563517² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665365563917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332682781758 + 332682781759.

It is an arithmetic number, because the mean of its divisors is an integer number (332682781759).

Almost surely, 2^665365563517 is an apocalyptic number.

It is an amenable number.

665365563517 is a deficient number, since it is larger than the sum of its proper divisors (1).

665365563517 is an equidigital number, since it uses as much as digits as its factorization.

665365563517 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51030000, while the sum is 58.

The spelling of 665365563517 in words is "six hundred sixty-five billion, three hundred sixty-five million, five hundred sixty-three thousand, five hundred seventeen".