665516660077 has 2 divisors, whose sum is σ = 665516660078. Its totient is φ = 665516660076.

The previous prime is 665516659987. The next prime is 665516660087. The reversal of 665516660077 is 770066615566.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 617805432036 + 47711228041 = 786006^2 + 218429^2 .

It is a cyclic number.

It is not a de Polignac number, because 665516660077 - 2²⁷ = 665382442349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665516660087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332758330038 + 332758330039.

It is an arithmetic number, because the mean of its divisors is an integer number (332758330039).

Almost surely, 2^665516660077 is an apocalyptic number.

It is an amenable number.

665516660077 is a deficient number, since it is larger than the sum of its proper divisors (1).

665516660077 is an equidigital number, since it uses as much as digits as its factorization.

665516660077 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9525600, while the sum is 55.

The spelling of 665516660077 in words is "six hundred sixty-five billion, five hundred sixteen million, six hundred sixty thousand, seventy-seven".