Q: Is 21,584 a Prime Number?
A: No, 21,584 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 21584 can be evenly divided by 1 2 4 8 16 19 38 71 76 142 152 284 304 568 1,136 1,349 2,698 5,396 10,792 and 21,584, with no remainder.
Since 21,584 cannot be divided by just 1 and 21,584, it is not a prime number.