Q: Is 21,328 a Prime Number?
A: No, 21,328 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 21328 can be evenly divided by 1 2 4 8 16 31 43 62 86 124 172 248 344 496 688 1,333 2,666 5,332 10,664 and 21,328, with no remainder.
Since 21,328 cannot be divided by just 1 and 21,328, it is not a prime number.