popularity vs popular

popularity is a noun but popular is not a noun.

Word	Noun	Adjective	Verb	Adverb
popularity	Yes	No	No	No
popular	No	Yes	No	No

popularity (noun)	popular (noun)
the quality of being widely admired or accepted or sought after

popularity (adjective)	popular (adjective)
	regarded with great favor, approval, or affection especially by the general public
	carried on by or for the people (or citizens) at large
	(of music or art) new and of general appeal (especially among young people)
	representing or appealing to or adapted for the benefit of the people at large