The number of chapters in Stephen King's novels varies widely. Some might have only a dozen or so, while others could have several dozen. It really depends on the specific work.
The number of drafts Stephen King writes depends on the complexity and his inspiration for each novel. Some might require three or four drafts, but there's no fixed number.
I'm not sure of the precise count, but a lot of Stephen King's works have been optioned. His novels often attract the attention of filmmakers and producers due to their engaging stories and wide appeal.