660808109 has 16 divisors (see below), whose sum is σ = 728179200. Its totient is φ = 595850880.

The previous prime is 660808097. The next prime is 660808151. The reversal of 660808109 is 901808066.

660808109 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 660808109 - 2²⁰ = 659759533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660808199) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 629417 + ... + 630465.

It is an arithmetic number, because the mean of its divisors is an integer number (45511200).

Almost surely, 2^660808109 is an apocalyptic number.

It is an amenable number.

660808109 is a deficient number, since it is larger than the sum of its proper divisors (67371091).

660808109 is a wasteful number, since it uses less digits than its factorization.

660808109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2140.

The product of its (nonzero) digits is 20736, while the sum is 38.

The square root of 660808109 is about 25706.1881460476. The cubic root of 660808109 is about 871.0139712503.

The spelling of 660808109 in words is "six hundred sixty million, eight hundred eight thousand, one hundred nine".