thirty-nine vs 39

thirty-nine and 39 both are adjectives.

Word	Noun	Adjective	Verb	Adverb
thirty-nine	No	Yes	No	No
39	No	Yes	No	No

As adjectives, thirty-nine and 39 are synonyms defined as:

Other synonyms of thirty-nine include ixl.

thirty-nine (adjective)	39 (adjective)
being nine more than thirty	being nine more than thirty