Well it would be an impressive feat, regardless. But of course there are a lot of degrees-of-freedom if you were to attempt this. Tiny formatting and encoding d

Well it would be an impressive feat, regardless. But of course there are a lot of degrees-of-freedom if you were to attempt this. Tiny formatting and encoding decisions would all greatly influence the resulting integer. Because it's so sensitive to chosen input, I would say even if you managed to produce a prime, it's not very satisfying as a sort of Godly checksum and signature. Much more interesting is to discover a new communication, a message encoded in a very large number that is distinguished by being prime. (What message would you send? It would be interesting if it ultimately described some sort of recursive, reactive automata, the source code for a kind of learning, communicating intelligence. A gift, then. An awesome, terrible gift.)