I have stumbled upon few versions of what appears to be a word to call upon or invoke: kaleo, anakaleo, epikaleo, katakaleo, parakaleo. Obviously kaleo would simply mean “call” in its most basic form, whereas the remaining four use prefixes ana-, epi-, kata-, and para-.
What would be the differences in meaning (or usage) between these four words? Could they be used interchangeably or each one of them belongs to a specific context?
If you enter καλέω into a search, you could end up here. Prefixed forms like the ones you are asking about are listed a ways down on the page, and the blue ones are linked to the LSJ so you can get an idea of the meaning.
Always keep in mind that meaning and use can only really be defined in terms of what the language does. Try to define the different meanings of “take” in “take off” (a plane, a hat), “take out” (a pizza, a date) “take over” (a government), “take up” (a hobby) etc.