A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7051176 can be evenly divided by 1 2 3 4 6 8 9 11 12 18 22 24 29 33 36 44 58 66 72 87 88 99 116 132 174 198 232 261 264 307 319 348 396 522 614 638 696 792 921 957 1,044 1,228 1,276 1,842 1,914 2,088 2,456 2,552 2,763 2,871 3,377 3,684 3,828 5,526 5,742 6,754 7,368 7,656 8,903 10,131 11,052 11,484 13,508 17,806 20,262 22,104 22,968 26,709 27,016 30,393 35,612 40,524 53,418 60,786 71,224 80,127 81,048 97,933 106,836 121,572 160,254 195,866 213,672 243,144 293,799 320,508 391,732 587,598 641,016 783,464 881,397 1,175,196 1,762,794 2,350,392 3,525,588 and 7,051,176, with no remainder.
Since 7,051,176 cannot be divided by just 1 and 7,051,176, it is not a prime number.