666785587666 has 8 divisors (see below), whose sum is σ = 1091103688944. Its totient is φ = 303084358020.

The previous prime is 666785587649. The next prime is 666785587667.

666785587666 is nontrivially palindromic in base 10.

666785587666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 666785587592 and 666785587601.

It is not an unprimeable number, because it can be changed into a prime (666785587667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15154217880 + ... + 15154217923.

It is an arithmetic number, because the mean of its divisors is an integer number (136387961118).

Almost surely, 2^666785587666 is an apocalyptic number.

666785587666 is a deficient number, since it is larger than the sum of its proper divisors (424318101278).

666785587666 is a wasteful number, since it uses less digits than its factorization.

666785587666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30308435816.

The product of its digits is 3657830400, while the sum is 76.

The spelling of 666785587666 in words is "six hundred sixty-six billion, seven hundred eighty-five million, five hundred eighty-seven thousand, six hundred sixty-six".