666685767 has 16 divisors (see below), whose sum is σ = 971868672. Its totient is φ = 403158720.

The previous prime is 666685759. The next prime is 666685769. The reversal of 666685767 is 767586666.

It is a happy number.

It is not a de Polignac number, because 666685767 - 2³ = 666685759 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666685769) 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 15 ways as a sum of consecutive naturals, for example, 7023 + ... + 37184.

It is an arithmetic number, because the mean of its divisors is an integer number (60741792).

Almost surely, 2^666685767 is an apocalyptic number.

666685767 is a deficient number, since it is larger than the sum of its proper divisors (305182905).

666685767 is a wasteful number, since it uses less digits than its factorization.

666685767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44678.

The product of its digits is 15240960, while the sum is 57.

The square root of 666685767 is about 25820.2588484314. The cubic root of 666685767 is about 873.5888074957.

The spelling of 666685767 in words is "six hundred sixty-six million, six hundred eighty-five thousand, seven hundred sixty-seven".