6686666865 has 48 divisors (see below), whose sum is σ = 12917923200. Its totient is φ = 3179782656.

The previous prime is 6686666843. The next prime is 6686666879. The reversal of 6686666865 is 5686666866.

It is not a de Polignac number, because 6686666865 - 2¹⁹ = 6686142577 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 215485 + ... + 244554.

It is an arithmetic number, because the mean of its divisors is an integer number (269123400).

Almost surely, 2^6686666865 is an apocalyptic number.

It is an amenable number.

6686666865 is a deficient number, since it is larger than the sum of its proper divisors (6231256335).

6686666865 is a wasteful number, since it uses less digits than its factorization.

6686666865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 460086 (or 460083 counting only the distinct ones).

The product of its digits is 89579520, while the sum is 63.

The square root of 6686666865 is about 81772.0420742933. The cubic root of 6686666865 is about 1883.9522695049.

Subtracting from 6686666865 its reverse (5686666866), we obtain a palindrome (999999999).

The spelling of 6686666865 in words is "six billion, six hundred eighty-six million, six hundred sixty-six thousand, eight hundred sixty-five".