Q: Is 1,666,509 a Prime Number?
A: No, 1,666,509 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 1666509 can be evenly divided by 1 3 13 19 39 57 169 173 247 507 519 741 2,249 3,211 3,287 6,747 9,633 9,861 29,237 42,731 87,711 128,193 555,503 and 1,666,509, with no remainder.
Since 1,666,509 cannot be divided by just 1 and 1,666,509, it is not a prime number.