220 simply means 22 x 100 = 22 ... uF , pF ... up to the size of the capacitor... at that size it's more likely to be 22uF, it's too large to be pF.
821 would mean 82 x 101 = 820uF etc etc
as for the voltage... since they're near a chipset or some chip/controller etc... the voltages are probably around 0.8-1.8v so they're probably rated for 2-2.5v ... can't be sure without actually probing or without checking chips around the area (see maybe there's a switching voltage regulator and maybe you can determine the voltage based on its datasheet and surrounding parts)