Q: Is 721,420 a Prime Number?
A: No, 721,420 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 721420 can be evenly divided by 1 2 4 5 7 10 14 20 28 35 70 140 5,153 10,306 20,612 25,765 36,071 51,530 72,142 103,060 144,284 180,355 360,710 and 721,420, with no remainder.
Since 721,420 cannot be divided by just 1 and 721,420, it is not a prime number.