Ummm, satan is a demon, and he (as Lucifer) was an angel at one time.. And his fellow demons were also angels at one point. They are the 1/3 of the angels who rebelled and were cast down with Lucifer.
No he is not.
Satan is the devil and there is just one of him.
You can find that out with a short study on the subject.
Yes, a third of the angels rebelled but that is not the end of the story.
No use trying to state otherwise I guess since you have 'corrected' me a few times now regarding the subject of the devil
curious why you would do that? please understand that the Bible is clear on the fact there is but one devil . Study in the original languages and you will find that to be true