A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7907040 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 16 17 18 19 20 24 30 32 34 36 38 40 45 48 51 57 60 68 72 76 80 85 90 95 96 102 114 120 136 144 152 153 160 170 171 180 190 204 228 240 255 272 285 288 289 304 306 323 340 342 360 380 408 456 480 510 544 570 578 608 612 646 680 684 720 760 765 816 855 867 912 969 1,020 1,140 1,156 1,224 1,292 1,360 1,368 1,440 1,445 1,520 1,530 1,615 1,632 1,710 1,734 1,824 1,938 2,040 2,280 2,312 2,448 2,584 2,601 2,720 2,736 2,890 2,907 3,040 3,060 3,230 3,420 3,468 3,876 4,080 4,335 4,560 4,624 4,845 4,896 5,168 5,202 5,472 5,491 5,780 5,814 6,120 6,460 6,840 6,936 7,752 8,160 8,670 9,120 9,248 9,690 10,336 10,404 10,982 11,560 11,628 12,240 12,920 13,005 13,680 13,872 14,535 15,504 16,473 17,340 19,380 20,808 21,964 23,120 23,256 24,480 25,840 26,010 27,360 27,455 27,744 29,070 31,008 32,946 34,680 38,760 41,616 43,928 46,240 46,512 49,419 51,680 52,020 54,910 58,140 65,892 69,360 77,520 82,365 83,232 87,856 93,024 98,838 104,040 109,820 116,280 131,784 138,720 155,040 164,730 175,712 197,676 208,080 219,640 232,560 247,095 263,568 329,460 395,352 416,160 439,280 465,120 494,190 527,136 658,920 790,704 878,560 988,380 1,317,840 1,581,408 1,976,760 2,635,680 3,953,520 and 7,907,040, with no remainder.
Since 7,907,040 cannot be divided by just 1 and 7,907,040, it is not a prime number.