686681207 has 4 divisors (see below), whose sum is σ = 687487080. Its totient is φ = 685875336.

The previous prime is 686681189. The next prime is 686681213. The reversal of 686681207 is 702186686.

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 686681207 - 2¹² = 686677111 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686681287) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 401657 + ... + 403362.

It is an arithmetic number, because the mean of its divisors is an integer number (171871770).

Almost surely, 2^686681207 is an apocalyptic number.

686681207 is a deficient number, since it is larger than the sum of its proper divisors (805873).

686681207 is an equidigital number, since it uses as much as digits as its factorization.

686681207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 805872.

The product of its (nonzero) digits is 193536, while the sum is 44.

The square root of 686681207 is about 26204.6027827174. The cubic root of 686681207 is about 882.2365659145.

The spelling of 686681207 in words is "six hundred eighty-six million, six hundred eighty-one thousand, two hundred seven".