A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1068144 can be evenly divided by 1 2 3 4 6 7 8 11 12 14 16 17 21 22 24 28 33 34 42 44 48 51 56 66 68 77 84 88 102 112 119 132 136 154 168 176 187 204 231 238 264 272 289 308 336 357 374 408 462 476 528 561 578 616 714 748 816 867 924 952 1,122 1,156 1,232 1,309 1,428 1,496 1,734 1,848 1,904 2,023 2,244 2,312 2,618 2,856 2,992 3,179 3,468 3,696 3,927 4,046 4,488 4,624 5,236 5,712 6,069 6,358 6,936 7,854 8,092 8,976 9,537 10,472 12,138 12,716 13,872 15,708 16,184 19,074 20,944 22,253 24,276 25,432 31,416 32,368 38,148 44,506 48,552 50,864 62,832 66,759 76,296 89,012 97,104 133,518 152,592 178,024 267,036 356,048 534,072 and 1,068,144, with no remainder.
Since 1,068,144 cannot be divided by just 1 and 1,068,144, it is not a prime number.