665665650577 has 2 divisors, whose sum is σ = 665665650578. Its totient is φ = 665665650576.

The previous prime is 665665650479. The next prime is 665665650583. The reversal of 665665650577 is 775056566566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 662569952256 + 3095698321 = 813984^2 + 55639^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665665650577 is a prime.

It is a super-2 number, since 2×665665650577² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (665665650077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332832825288 + 332832825289.

It is an arithmetic number, because the mean of its divisors is an integer number (332832825289).

Almost surely, 2^665665650577 is an apocalyptic number.

It is an amenable number.

665665650577 is a deficient number, since it is larger than the sum of its proper divisors (1).

665665650577 is an equidigital number, since it uses as much as digits as its factorization.

665665650577 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 238140000, while the sum is 64.

The spelling of 665665650577 in words is "six hundred sixty-five billion, six hundred sixty-five million, six hundred fifty thousand, five hundred seventy-seven".