Fix septillion and sextillion being swapped

numbers.js

@@ -26,8 +26,8 @@ _numberWords = {
   3: "trillion",
   4: "quadrillion",
   5: "quintillion",
-  6: "septillion",
-  7: "sextillion",
+  6: "sextillion",
+  7: "septillion",
   8: "octillion",
   9: "nonillion",
   10: "decillion",