Q: Is 213,721 a Prime Number?
A: Yes, 213,721 is a prime number.
A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 213721 can be evenly divided by 1 and 213,721, with no remainder.
Since 213,721 can be divided by just 1 and 213,721, it is a prime number.