A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8372160 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 16 17 18 19 20 24 27 30 32 34 36 38 40 45 48 51 54 57 60 64 68 72 76 80 81 85 90 95 96 102 108 114 120 135 136 144 152 153 160 162 170 171 180 190 192 204 216 228 240 255 270 272 285 288 304 306 320 323 324 340 342 360 380 405 408 432 456 459 480 510 513 540 544 570 576 608 612 646 648 680 684 720 760 765 810 816 855 864 912 918 960 969 1,020 1,026 1,080 1,088 1,140 1,216 1,224 1,292 1,296 1,360 1,368 1,377 1,440 1,520 1,530 1,539 1,615 1,620 1,632 1,710 1,728 1,824 1,836 1,938 2,040 2,052 2,160 2,280 2,295 2,448 2,565 2,584 2,592 2,720 2,736 2,754 2,880 2,907 3,040 3,060 3,078 3,230 3,240 3,264 3,420 3,648 3,672 3,876 4,080 4,104 4,320 4,560 4,590 4,845 4,896 5,130 5,168 5,184 5,440 5,472 5,508 5,814 6,080 6,120 6,156 6,460 6,480 6,840 6,885 7,344 7,695 7,752 8,160 8,208 8,640 8,721 9,120 9,180 9,690 9,792 10,260 10,336 10,944 11,016 11,628 12,240 12,312 12,920 12,960 13,680 13,770 14,535 14,688 15,390 15,504 16,320 16,416 17,442 18,240 18,360 19,380 20,520 20,672 22,032 23,256 24,480 24,624 25,840 25,920 26,163 27,360 27,540 29,070 29,376 30,780 31,008 32,832 34,884 36,720 38,760 41,040 43,605 44,064 46,512 48,960 49,248 51,680 52,326 54,720 55,080 58,140 61,560 62,016 69,768 73,440 77,520 82,080 87,210 88,128 93,024 98,496 103,360 104,652 110,160 116,280 123,120 130,815 139,536 146,880 155,040 164,160 174,420 186,048 209,304 220,320 232,560 246,240 261,630 279,072 310,080 348,840 418,608 440,640 465,120 492,480 523,260 558,144 697,680 837,216 930,240 1,046,520 1,395,360 1,674,432 2,093,040 2,790,720 4,186,080 and 8,372,160, with no remainder.
Since 8,372,160 cannot be divided by just 1 and 8,372,160, it is not a prime number.