866686680679 has 4 divisors (see below), whose sum is σ = 875101114576. Its totient is φ = 858272246784.

The previous prime is 866686680649. The next prime is 866686680707. The reversal of 866686680679 is 976086686668.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 866686680679 - 2⁷ = 866686680551 is a prime.

It is a super-2 number, since 2×866686680679² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866686680619) 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, 4207216794 + ... + 4207216999.

It is an arithmetic number, because the mean of its divisors is an integer number (218775278644).

Almost surely, 2^866686680679 is an apocalyptic number.

866686680679 is a deficient number, since it is larger than the sum of its proper divisors (8414433897).

866686680679 is a wasteful number, since it uses less digits than its factorization.

866686680679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8414433896.

The product of its (nonzero) digits is 1504935936, while the sum is 76.

The spelling of 866686680679 in words is "eight hundred sixty-six billion, six hundred eighty-six million, six hundred eighty thousand, six hundred seventy-nine".