663665065 has 12 divisors (see below), whose sum is σ = 926422596. Its totient is φ = 455084448.

The previous prime is 663665059. The next prime is 663665089. The reversal of 663665065 is 560566366.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 348531561 + 315133504 = 18669^2 + 17752^2 .

It is not a de Polignac number, because 663665065 - 2¹⁷ = 663533993 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1354174 + ... + 1354663.

It is an arithmetic number, because the mean of its divisors is an integer number (77201883).

Almost surely, 2^663665065 is an apocalyptic number.

It is an amenable number.

663665065 is a deficient number, since it is larger than the sum of its proper divisors (262757531).

663665065 is a wasteful number, since it uses less digits than its factorization.

663665065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2708856 (or 2708849 counting only the distinct ones).

The product of its (nonzero) digits is 583200, while the sum is 43.

The square root of 663665065 is about 25761.6976342787. The cubic root of 663665065 is about 872.2674218549.

The spelling of 663665065 in words is "six hundred sixty-three million, six hundred sixty-five thousand, sixty-five".