Q: Is 1,621,605 a Prime Number?
A: No, 1,621,605 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 1621605 can be evenly divided by 1 3 5 15 108,107 324,321 540,535 and 1,621,605, with no remainder.
Since 1,621,605 cannot be divided by just 1 and 1,621,605, it is not a prime number.