A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8274816 can be evenly divided by 1 2 3 4 6 8 9 11 12 16 18 22 24 32 33 36 44 48 64 66 72 88 96 99 128 132 144 176 192 198 264 288 352 384 396 528 576 653 704 792 1,056 1,152 1,306 1,408 1,584 1,959 2,112 2,612 3,168 3,918 4,224 5,224 5,877 6,336 7,183 7,836 10,448 11,754 12,672 14,366 15,672 20,896 21,549 23,508 28,732 31,344 41,792 43,098 47,016 57,464 62,688 64,647 83,584 86,196 94,032 114,928 125,376 129,294 172,392 188,064 229,856 250,752 258,588 344,784 376,128 459,712 517,176 689,568 752,256 919,424 1,034,352 1,379,136 2,068,704 2,758,272 4,137,408 and 8,274,816, with no remainder.
Since 8,274,816 cannot be divided by just 1 and 8,274,816, it is not a prime number.