favor vs prefer

favor is a noun but prefer is not a noun.

Word	Noun	Adjective	Verb	Adverb
favor	Yes	No	Yes	No
prefer	No	No	Yes	No

As verbs, favor and prefer are synonyms defined as:

Other synonyms of favor include favour.

favor (noun)	prefer (noun)
an act of gracious kindness
souvenir consisting of a small gift given to a guest at a party
an advantage to the benefit of someone or something
an inclination to approve
a feeling of favorable regard

favor (verb)	prefer (verb)
consider as the favorite	select as an alternative over another
promote over another	like better; value more highly
treat gently or carefully	promote over another
bestow a privilege upon	give preference to one creditor over another