Q: Is 21,455 a Prime Number?
A: No, 21,455 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 21455 can be evenly divided by 1 5 7 35 613 3,065 4,291 and 21,455, with no remainder.
Since 21,455 cannot be divided by just 1 and 21,455, it is not a prime number.