A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 683298 can be evenly divided by 1 2 3 6 7 9 11 14 17 18 21 22 29 33 34 42 51 58 63 66 77 87 99 102 119 126 153 154 174 187 198 203 231 238 261 306 319 357 374 406 462 493 522 561 609 638 693 714 957 986 1,071 1,122 1,218 1,309 1,386 1,479 1,683 1,827 1,914 2,142 2,233 2,618 2,871 2,958 3,366 3,451 3,654 3,927 4,437 4,466 5,423 5,742 6,699 6,902 7,854 8,874 10,353 10,846 11,781 13,398 16,269 20,097 20,706 23,562 31,059 32,538 37,961 40,194 48,807 62,118 75,922 97,614 113,883 227,766 341,649 and 683,298, with no remainder.
Since 683,298 cannot be divided by just 1 and 683,298, it is not a prime number.