Q: Is 21,381 a Prime Number?
A: No, 21,381 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 21381 can be evenly divided by 1 3 7,127 and 21,381, with no remainder.
Since 21,381 cannot be divided by just 1 and 21,381, it is not a prime number.