Q: Is 646 a Prime Number?
A: No, 646 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 646 can be evenly divided by 1 2 17 19 34 38 323 and 646, with no remainder.
Since 646 cannot be divided by just 1 and 646, it is not a prime number.