Q: Is 21,981 a Prime Number?
A: No, 21,981 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 21981 can be evenly divided by 1 3 17 51 431 1,293 7,327 and 21,981, with no remainder.
Since 21,981 cannot be divided by just 1 and 21,981, it is not a prime number.