call up vs invoke

call up is a noun but invoke is not a noun.

Word	Noun	Adjective	Verb	Adverb
call up	Yes	No	Yes	No
invoke	No	No	Yes	No

As verbs, invoke is a hyponym of call up; that is, invoke is a word with a more specific, narrower meaning than call up:

call up: cause to become available for use, either literally or figuratively
invoke: summon into action or bring into existence, often as if by magic

Other hyponyms of call up include arouse, bring up, call down, call forth, conjure, conjure up, evoke, put forward, raise, stir.

call up (noun)	invoke (noun)
an order to report for military duty

call up (verb)	invoke (verb)
recall knowledge from memory; have a recollection	cite as an authority; resort to
get or try to get into communication (with someone) by telephone	request earnestly (something from somebody); ask for aid or protection
bring forward for consideration	summon into action or bring into existence, often as if by magic
call to arms; of military personnel
cause to become available for use, either literally or figuratively