Not
A example of a word with non- as a prefix meaning nine would be like Nonagon- meaning a shape with 9 sides non-smart-meaning having no knowledge
No/not /not having/ It makes a word negative, or opposite in meaning e.g. non-proliferation, non-negotiable, non-commital, nonsense, nonentity.
account originates from the word "conter" (fr.: to count) the prefix a/ad means "to" (from Latin, through French)
mulit means many of something and the word is a prefix