Nothing is noted on any major websites. These coins are very heavy and are often subject to "bag marks" even in uncirculated condition, so it's possible you simply have damage that occurred then the coins were being processed after minting.
FWIW, the coin is a DOLLAR, just like it's spelled on the coin, and a mistake would be MIS-STRUCK. For some reason coins are said to be struck or minted, while ordinary objects like spoons, car fenders, etc. are "stamped"
Circulated coins are valued at $14.00-$19.00
If it has the tails image on both sides, how do you know its date is 1921? In any case if both sides are the same it's a prank coin made by joining halves of 2 genuine coins and has no numismatic value. The good news is that its silver content might be worth $13-$15. BTW, coins are minted or struck rather than "stamped"
There is around .77 ounces in a 1921 US silver dollar.
armscollectors.com Remington's are date code stamped from 1921 details on Remington Society of America.
If it has 3 clearly repunched mintmark images, it will be worth about $30 in circulated condition.
In the search box on your browser type in 1921 silver dollars and click on images.
There is .77344 of a Troy ounce (a little than 24 grams) of pure silver in a 1921 U.S. silver dollar.
A 1921 Morgan dollar is worth about $25.00
United States silver Peace Dollars were minted from 1921 through 1935.
A 1921 Mexican 1 Peso coin contains 0.3856 troy ounces of silver.
Silver Threads Among the Gold - 1921 is rated/received certificates of: UK:U
A 1921 Morgan silver dollar contains 90% silver and weighs approximately 26.73 grams in total. To calculate the amount of silver in the coin: 90% of 26.73 grams = 24.06 grams of silver. So, a 1921 Morgan silver dollar has about 24.06 grams of silver.