Q: Is 21,123 a Prime Number?
A: No, 21,123 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 21123 can be evenly divided by 1 3 9 2,347 7,041 and 21,123, with no remainder.
Since 21,123 cannot be divided by just 1 and 21,123, it is not a prime number.