665128117769 has 2 divisors, whose sum is σ = 665128117770. Its totient is φ = 665128117768.

The previous prime is 665128117729. The next prime is 665128117873. The reversal of 665128117769 is 967711821566.

It is a happy number.

665128117769 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 460751791369 + 204376326400 = 678787^2 + 452080^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665128117769 is a prime.

It is a super-2 number, since 2×665128117769² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (665128117729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332564058884 + 332564058885.

It is an arithmetic number, because the mean of its divisors is an integer number (332564058885).

Almost surely, 2^665128117769 is an apocalyptic number.

It is an amenable number.

665128117769 is a deficient number, since it is larger than the sum of its proper divisors (1).

665128117769 is an equidigital number, since it uses as much as digits as its factorization.

665128117769 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7620480, while the sum is 59.

The spelling of 665128117769 in words is "six hundred sixty-five billion, one hundred twenty-eight million, one hundred seventeen thousand, seven hundred sixty-nine".