The number 687 is an integer that follows 686 and precedes 688. It is an odd number and can be factored into prime numbers as 7 × 7 × 13. In mathematics, it is often used in various calculations and can represent quantities in different contexts. In terms of its significance, 687 is also notable in other fields. For example, it is the designation for certain models of vehicles, such as the Boeing 687, and can refer to specific years in history, like AD 687, which saw various events in different cultures.