content word vs numeral

content word and numeral both are nouns.

Word	Noun	Adjective	Verb	Adverb
content word	Yes	No	No	No
numeral	Yes	Yes	No	No

As nouns, numeral is a hyponym of content word; that is, numeral is a word with a more specific, narrower meaning than content word:

Other hyponyms of content word include head word, headword, noun, verb, modifier, qualifier.

content word (noun)	numeral (noun)
a word to which an independent meaning can be assigned	a symbol used to represent a number
	a word expressing a number.

content word (adjective)	numeral (adjective)
	of or relating to or denoting numbers