A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7963480 can be evenly divided by 1 2 4 5 7 8 10 14 17 20 28 34 35 40 49 56 68 70 85 98 119 136 140 170 196 238 239 245 280 340 392 476 478 490 595 680 833 952 956 980 1,190 1,195 1,666 1,673 1,912 1,960 2,380 2,390 3,332 3,346 4,063 4,165 4,760 4,780 6,664 6,692 8,126 8,330 8,365 9,560 11,711 13,384 16,252 16,660 16,730 20,315 23,422 28,441 32,504 33,320 33,460 40,630 46,844 56,882 58,555 66,920 81,260 93,688 113,764 117,110 142,205 162,520 199,087 227,528 234,220 284,410 398,174 468,440 568,820 796,348 995,435 1,137,640 1,592,696 1,990,870 3,981,740 and 7,963,480, with no remainder.
Since 7,963,480 cannot be divided by just 1 and 7,963,480, it is not a prime number.