Q: Is 428,639 a Prime Number?
A: Yes, 428,639 is a prime number.
A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 428639 can be evenly divided by 1 and 428,639, with no remainder.
Since 428,639 can be divided by just 1 and 428,639, it is a prime number.