Q: Is 21,858 a Prime Number?
A: No, 21,858 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 21858 can be evenly divided by 1 2 3 6 3,643 7,286 10,929 and 21,858, with no remainder.
Since 21,858 cannot be divided by just 1 and 21,858, it is not a prime number.