How many earth years does it take Neptune to orbit the Sun?

Dark, cold, and whipped by supersonic winds, ice giant Neptune is the eighth and most distant planet in our solar system. More than 30 times as far from the Sun as Earth, Neptune is the only planet in our solar system not visible to the naked eye and the first predicted by mathematics before its discovery. The Distance from Sun is 4.495 billion km, that's why it takes so much time to orbit the Sun.

Also the gravitational force of the Sun is much weaker in long distances.