Q: Is 21,808 a Prime Number?
A: No, 21,808 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 21808 can be evenly divided by 1 2 4 8 16 29 47 58 94 116 188 232 376 464 752 1,363 2,726 5,452 10,904 and 21,808, with no remainder.
Since 21,808 cannot be divided by just 1 and 21,808, it is not a prime number.