OK, I've clicked on your name to find your home page.
You're not a troll :-)
Are there any commercial applications of their discovery--say, in encryption?
[Other countries may have caught up with the US on nukes
but we still have WAY more lawyers ;-) ]
Assuming that you are asking about Dr. Agarwal's recent discovery and not Ramanujan's body of work, I cannot think of any commercial impact except potentially to a specialized company like RSA.
RSA is a company built around the idea that factoring is hard; approaches to factoring often involve determining if various numbers are prime.
So, yes, it could potentially have some commercial impact (most likely negative, though), though I don't believe that anyone has done anything yet that would have impact on RSA.
There are also potential (very low likelihood) national security implications to the extent that any of our crypto systems might also be weakened -- but this is not so likely since excellent probabilistic primality tests already existed, such as Rabin-Miller.
But it is a good result, one that people have looked a long time for. It's a fundamental result, so something else could be built on top of it that could have a big impact.