A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6814008 can be evenly divided by 1 2 3 4 6 8 9 12 17 18 19 24 34 36 38 51 57 68 72 76 102 114 136 152 153 171 204 228 293 306 323 342 408 456 586 612 646 684 879 969 1,172 1,224 1,292 1,368 1,758 1,938 2,344 2,584 2,637 2,907 3,516 3,876 4,981 5,274 5,567 5,814 7,032 7,752 9,962 10,548 11,134 11,628 14,943 16,701 19,924 21,096 22,268 23,256 29,886 33,402 39,848 44,536 44,829 50,103 59,772 66,804 89,658 94,639 100,206 119,544 133,608 179,316 189,278 200,412 283,917 358,632 378,556 400,824 567,834 757,112 851,751 1,135,668 1,703,502 2,271,336 3,407,004 and 6,814,008, with no remainder.
Since 6,814,008 cannot be divided by just 1 and 6,814,008, it is not a prime number.