What’s fun is that you can actually ATTEMPT to run these computations in Wolfram|Alpha. Here’s mercury in 1 billion years. Unfortunately the one thing I want to be able to show is the orbits of the planets and that is pushing W|A to the heuristic timing limit.
I can put this into Mathematica and work it out using more local CPU power. Then again, I like just playing with numbers to see where I can take this. Here’s Mercury at 199,999 years. Things get gnarly.