A Thousand Years
(Rev. 20:2 KJV) 2 And he laid hold on the dragon, that old serpent, which is the Devil, and Satan, and bound him a thousand years,
The 1000 years is the millennium kingdom. Some believe the wording is figurative and just means a very long period of time. Some believe it is literal. Either way, Satan will be bound into prison for that time and he won’t be able to deceive the nations during that time.