686666686 has 16 divisors (see below), whose sum is σ = 1101836736. Its totient is φ = 319804416.

The previous prime is 686666671. The next prime is 686666711.

686666686 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×686666686² = 943022275324445192, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 686666686.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 100806 + ... + 107401.

It is an arithmetic number, because the mean of its divisors is an integer number (68864796).

Almost surely, 2^686666686 is an apocalyptic number.

686666686 is a deficient number, since it is larger than the sum of its proper divisors (415170050).

686666686 is a wasteful number, since it uses less digits than its factorization.

686666686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208323.

The product of its digits is 17915904, while the sum is 58.

The square root of 686666686 is about 26204.3257116072. The cubic root of 686666686 is about 882.2303470911.

The spelling of 686666686 in words is "six hundred eighty-six million, six hundred sixty-six thousand, six hundred eighty-six".