A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2319174 can be evenly divided by 1 2 3 6 9 11 13 17 18 22 26 33 34 39 51 53 66 78 99 102 106 117 143 153 159 187 198 221 234 286 306 318 374 429 442 477 561 583 663 689 858 901 954 1,122 1,166 1,287 1,326 1,378 1,683 1,749 1,802 1,989 2,067 2,431 2,574 2,703 3,366 3,498 3,978 4,134 4,862 5,247 5,406 6,201 7,293 7,579 8,109 9,911 10,494 11,713 12,402 14,586 15,158 16,218 19,822 21,879 22,737 23,426 29,733 35,139 43,758 45,474 59,466 68,211 70,278 89,199 105,417 128,843 136,422 178,398 210,834 257,686 386,529 773,058 1,159,587 and 2,319,174, with no remainder.
Since 2,319,174 cannot be divided by just 1 and 2,319,174, it is not a prime number.