Higher-denomination broadstruck coins such as yours can be worth in excess of $200. If the design is well-centered within the extended planchet, it can be worth even more.
To have a more specific idea you'd need to get a couple of competing estimates from dealers who specialize in error coins.
The is no 1921S Peace dollar; Peace dollars were not produced in San Francisco ("S" mintmark) in 1921. If your 1921 dollar coin is a Peace dollar, it was produced in Philadelphia and has no mintmark; if it has an "S" mintmark, it is a Morgan dollar produced in San Francisco).
They stopped making the Peace dollar in 1935.
The image on the 1923 Peace Dollar is that of Lady Liberty.
The 1921 Peace dollar was minted to commemorate the end of World War I.
The last Peace dollar was issued in 1935 so it can't be a 1942 Peace dollar. Look at the coin again and post new question.
On your browser type in " Peace Dollar " and click on images, this is the easy thing to do.
Type in Peace dollar in your browser and click images.
It looks the same as any other Peace dollar.
"Paix éternelle"
Peace on Earth
A 1923 Peace dollar is very common and has values of $25.00-$27.00 in circulated condition.
1921 was the first year issue for the Peace dollar and the last year for the Morgan.