Q: Is 421,840 a Prime Number?
A: No, 421,840 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 421840 can be evenly divided by 1 2 4 5 8 10 16 20 40 80 5,273 10,546 21,092 26,365 42,184 52,730 84,368 105,460 210,920 and 421,840, with no remainder.
Since 421,840 cannot be divided by just 1 and 421,840, it is not a prime number.