Q: Is 421,668 a Prime Number?
A: No, 421,668 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 421668 can be evenly divided by 1 2 3 4 6 9 12 13 17 18 26 34 36 39 51 52 53 68 78 102 106 117 153 156 159 204 212 221 234 306 318 442 468 477 612 636 663 689 884 901 954 1,326 1,378 1,802 1,908 1,989 2,067 2,652 2,703 2,756 3,604 3,978 4,134 5,406 6,201 7,956 8,109 8,268 10,812 11,713 12,402 16,218 23,426 24,804 32,436 35,139 46,852 70,278 105,417 140,556 210,834 and 421,668, with no remainder.
Since 421,668 cannot be divided by just 1 and 421,668, it is not a prime number.