call on vs invoke

call on and invoke both are verbs.

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

As verbs, invoke is a hypernym of call on; that is, invoke is a word with a broader meaning than call on:

call on: have recourse to or make an appeal or request for help or information to
invoke: request earnestly (something from somebody); ask for aid or protection

Other hypernyms of call on include appeal.

call on (verb)	invoke (verb)
have recourse to or make an appeal or request for help or information to	cite as an authority; resort to
to visit someone, usually for a short time	request earnestly (something from somebody); ask for aid or protection
	summon into action or bring into existence, often as if by magic