twenty vs large integer

twenty and large integer both are nouns.

Word	Noun	Adjective	Verb	Adverb
twenty	Yes	Yes	No	No
large integer	Yes	No	No	No

As nouns, large integer is a hypernym of twenty; that is, large integer is a word with a broader meaning than twenty:

twenty (noun)	large integer (noun)
a United States bill worth 20 dollars	an integer equal to or greater than ten
the cardinal number that is the sum of nineteen and one

twenty (adjective)	large integer (adjective)
denoting a quantity consisting of 20 items or units