This is thanks to the wikipieda page about Planck mass, which can be found within the related links.
miligrams
it is about 0.5 milligrams
1 / 0.005 = 200
Yes, mass has mass. It is, therefore, matter. If mass did not have mass, then it is "something" with no mass. That would make it "non-matter" and perhaps it might be energy.
No. Fleas themselves cannot have fleas, but they can have these things called "mites".