They trademarked a very specific icon which happens to contain the digits 2, 8, and 0 in that order. (If you have an iOS device, it is your "Maps" icon.)
A bit of history: when AMD and Cyrix started gaining market share selling their x86 chips, Intel went to court to try to trademark "486" and failed, so the 586 became Pentium.
If the drug company that made the morning after birth control drug had not been able tom trademark RU-486, I wonder ifbtheymwould have called it Preventium?
There's a similar story that the Porsche 911 was originally going to be called 901, but that Peugeot had claimed all 3-digit numbers with a zero in the middle and forced Porsche to rename their model.