665996065 has 16 divisors (see below), whose sum is σ = 913790592. Its totient is φ = 456470784.

The previous prime is 665996057. The next prime is 665996077. The reversal of 665996065 is 560699566.

It is a happy number.

It is not a de Polignac number, because 665996065 - 2³ = 665996057 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 126822 + ... + 131968.

It is an arithmetic number, because the mean of its divisors is an integer number (57111912).

Almost surely, 2^665996065 is an apocalyptic number.

It is an amenable number.

665996065 is a deficient number, since it is larger than the sum of its proper divisors (247794527).

665996065 is a wasteful number, since it uses less digits than its factorization.

665996065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8856.

The product of its (nonzero) digits is 2624400, while the sum is 52.

The square root of 665996065 is about 25806.8995619389. The cubic root of 665996065 is about 873.2874542098.

The spelling of 665996065 in words is "six hundred sixty-five million, nine hundred ninety-six thousand, sixty-five".