Go ask one to its face. It'll either be mad that you implied it's less than human, or it'll be mad that you called it a person when it's so obviously superior to people.
Sapient creatures are people, yes. Especially when they speak human/humanoid language, which is true for many (most?) dragons in tabletop settings and even Lord of the Rings. In Faerun (D&D) they can even easily transform into humanoids.