Base 62, or duosexagesimal, is a counting system where A=10...Z=35,a=36...z=61. For example, "Marcus882" in base 10, converted from base 62, would be (2*62^0)+(8*62^1)+(8*62^2)+(54*62^3)+(56*62^4)+(38*62^5)+(53*62^6)+(36*62^7)+(22*62^8)=4,922,249,713,888,306, shortened to 4.92 quadrillion, approximately.