Q: Is 21,680 a Prime Number?
A: No, 21,680 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 21680 can be evenly divided by 1 2 4 5 8 10 16 20 40 80 271 542 1,084 1,355 2,168 2,710 4,336 5,420 10,840 and 21,680, with no remainder.
Since 21,680 cannot be divided by just 1 and 21,680, it is not a prime number.