A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1793568 can be evenly divided by 1 2 3 4 6 7 8 12 14 16 17 21 24 28 32 34 42 48 51 56 68 84 96 102 112 119 136 157 168 204 224 238 272 314 336 357 408 471 476 544 628 672 714 816 942 952 1,099 1,256 1,428 1,632 1,884 1,904 2,198 2,512 2,669 2,856 3,297 3,768 3,808 4,396 5,024 5,338 5,712 6,594 7,536 8,007 8,792 10,676 11,424 13,188 15,072 16,014 17,584 18,683 21,352 26,376 32,028 35,168 37,366 42,704 52,752 56,049 64,056 74,732 85,408 105,504 112,098 128,112 149,464 224,196 256,224 298,928 448,392 597,856 896,784 and 1,793,568, with no remainder.
Since 1,793,568 cannot be divided by just 1 and 1,793,568, it is not a prime number.