22 million digits is still small by cryptography standards.
It isn’t the logic behind a prime that is the hard part. Advanced logic must be created to shortcut the processing needed to find the prime. These numbers cannot be calculated directly and must be processed in chunks. That processing takes a looong time. So, the advanced math is about finding the next prime using math instead of processing.
I don’t think so!
22,000,000 the number is small by cryptography standards.
22,000,000 digits i.e. 10 raised to the 22,000,000 power? Not small.