659663966809 has 9 divisors (see below), whose sum is σ = 661717878453. Its totient is φ = 657616418172.

The previous prime is 659663966779. The next prime is 659663966813. The reversal of 659663966809 is 908669366956.

The square root of 659663966809 is 812197.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 659663966809 - 2⁵ = 659663966777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (659663966879) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 307821592 + ... + 307823734.

It is an arithmetic number, because the mean of its divisors is an integer number (73524208717).

Almost surely, 2^659663966809 is an apocalyptic number.

659663966809 is the 812197-th square number.

659663966809 is the 406099-th centered octagonal number.

It is an amenable number.

659663966809 is a deficient number, since it is larger than the sum of its proper divisors (2053911644).

659663966809 is an frugal number, since it uses more digits than its factorization.

659663966809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5044 (or 2522 counting only the distinct ones).

The product of its (nonzero) digits is 680244480, while the sum is 73.

The spelling of 659663966809 in words is "six hundred fifty-nine billion, six hundred sixty-three million, nine hundred sixty-six thousand, eight hundred nine".