hundred-and-ninetieth vs ordinal

hundred-and-ninetieth is not a noun while ordinal is a noun.

Word	Noun	Adjective	Verb	Adverb
hundred-and-ninetieth	No	Yes	No	No
ordinal	Yes	Yes	No	No

hundred-and-ninetieth (noun)	ordinal (noun)
	the number designating place in an ordered sequence

hundred-and-ninetieth (adjective)	ordinal (adjective)
the ordinal number of one hundred eighty-five in counting order	being or denoting a numerical order in a series
	of or relating to a taxonomic order