solved with wolframalpha.com: sum phi(n), n=2 to 1000000 3039650753 + 9118948164 + 15198149566 + 21277458826 + 27356832366 + 33435937046 + 39515212818 + 45594757684 + 51673635564 + 57752969604 ------------- 303963552391