They have won 18 league titles
Preston North End won the first 2 premier leagues (called First Division then). And if your talking first premier league as in the premiership then that was Man United in the early 90's.
man united have won the premier league 18 times
They have never won the Premier League.
Manchester United have won the Premier League 13 times.
37 times they are the best team in the premier league and always will be.