Q: Is 21,355 a Prime Number?
A: No, 21,355 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 21355 can be evenly divided by 1 5 4,271 and 21,355, with no remainder.
Since 21,355 cannot be divided by just 1 and 21,355, it is not a prime number.