Q: Is 21,309 a Prime Number?
A: No, 21,309 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 21309 can be evenly divided by 1 3 7,103 and 21,309, with no remainder.
Since 21,309 cannot be divided by just 1 and 21,309, it is not a prime number.