Number 687 is an integer that follows 686 and precedes 688. It is an odd number and can be expressed as the sum of two prime numbers, specifically 683 and 4. In mathematics, it is often used in various calculations and can be found in different contexts, such as statistics and number theory. In the realm of astronomy, 687 is also the designation for a minor planet known as Ceres. Discovered in 1908, it is part of the asteroid belt and has a diameter of approximately 100 kilometers. This celestial body contributes to our understanding of the solar system and the formation of planets.