940 A Mint Mark 5 Reichspfennig

The 1 appears to be almost gone the coin is in great condition for the 1 to be as faded as it is it's there but honesty it looks like is a ghost 1 there is nothing raised up but can barley see it somehow is this possible or is this a fake or something happen to it maybe idk ran across it other day I thought this is very interesting it's hard to see the one it's flat but it's barley there it's literally like a ghost 1