666865568666 has 16 divisors (see below), whose sum is σ = 1097768911680. Its totient is φ = 301305617280.

The previous prime is 666865568659. The next prime is 666865568669.

666865568666 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×666865568666² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 666865568593 and 666865568602.

It is not an unprimeable number, because it can be changed into a prime (666865568669) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 90751031 + ... + 90758378.

It is an arithmetic number, because the mean of its divisors is an integer number (68610556980).

Almost surely, 2^666865568666 is an apocalyptic number.

666865568666 is a deficient number, since it is larger than the sum of its proper divisors (430903343014).

666865568666 is a wasteful number, since it uses less digits than its factorization.

666865568666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181509589.

The product of its digits is 2687385600, while the sum is 74.

The spelling of 666865568666 in words is "six hundred sixty-six billion, eight hundred sixty-five million, five hundred sixty-eight thousand, six hundred sixty-six".