No, it is a joke!!. The calculator has a limit of about 10^372 display. Your number of e^1,000,000 is a far, far bigger number and it says "infinity". Most calculators have limited display built into them. Your e^1,000,000 is a very large number=3.033215396802087... × 10^434,294. As you can see, it has 434,295 digits!!!.