A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8444160 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 16 18 20 24 30 32 36 40 45 48 60 64 72 80 90 96 120 128 144 160 180 192 240 256 288 320 360 384 480 576 640 720 733 768 960 1,152 1,280 1,440 1,466 1,920 2,199 2,304 2,880 2,932 3,665 3,840 4,398 5,760 5,864 6,597 7,330 8,796 10,995 11,520 11,728 13,194 14,660 17,592 21,990 23,456 26,388 29,320 32,985 35,184 43,980 46,912 52,776 58,640 65,970 70,368 87,960 93,824 105,552 117,280 131,940 140,736 175,920 187,648 211,104 234,560 263,880 281,472 351,840 422,208 469,120 527,760 562,944 703,680 844,416 938,240 1,055,520 1,407,360 1,688,832 2,111,040 2,814,720 4,222,080 and 8,444,160, with no remainder.
Since 8,444,160 cannot be divided by just 1 and 8,444,160, it is not a prime number.