Q: Is 421,503 a Prime Number?
A: No, 421,503 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 421503 can be evenly divided by 1 3 109 327 1,289 3,867 140,501 and 421,503, with no remainder.
Since 421,503 cannot be divided by just 1 and 421,503, it is not a prime number.