Q: Is 420,503 a Prime Number?
A: Yes, 420,503 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 420503 can be evenly divided by 1 and 420,503, with no remainder.
Since 420,503 can be divided by just 1 and 420,503, it is a prime number.