665064078689 has 2 divisors, whose sum is σ = 665064078690. Its totient is φ = 665064078688.

The previous prime is 665064078671. The next prime is 665064078727. The reversal of 665064078689 is 986870460566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 414263438689 + 250800640000 = 643633^2 + 500800^2 .

It is a cyclic number.

It is not a de Polignac number, because 665064078689 - 2²⁸ = 664795643233 is a prime.

It is not a weakly prime, because it can be changed into another prime (665064078389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332532039344 + 332532039345.

It is an arithmetic number, because the mean of its divisors is an integer number (332532039345).

Almost surely, 2^665064078689 is an apocalyptic number.

It is an amenable number.

665064078689 is a deficient number, since it is larger than the sum of its proper divisors (1).

665064078689 is an equidigital number, since it uses as much as digits as its factorization.

665064078689 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 104509440, while the sum is 65.

The spelling of 665064078689 in words is "six hundred sixty-five billion, sixty-four million, seventy-eight thousand, six hundred eighty-nine".