Q: Is 21,231 a Prime Number?
A: No, 21,231 is not a prime number.
A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 21231 can be evenly divided by 1 3 7 9 21 63 337 1,011 2,359 3,033 7,077 and 21,231, with no remainder.
Since 21,231 cannot be divided by just 1 and 21,231, it is not a prime number.