A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7056720 can be evenly divided by 1 2 3 4 5 6 8 9 10 11 12 15 16 18 20 22 24 27 30 33 36 40 44 45 48 54 55 60 66 72 80 81 88 90 99 108 110 120 121 132 135 144 162 165 176 180 198 216 220 240 242 243 264 270 297 324 330 360 363 396 405 432 440 484 486 495 528 540 594 605 648 660 720 726 729 792 810 880 891 968 972 990 1,080 1,089 1,188 1,210 1,215 1,296 1,320 1,452 1,458 1,485 1,584 1,620 1,782 1,815 1,936 1,944 1,980 2,160 2,178 2,376 2,420 2,430 2,640 2,673 2,904 2,916 2,970 3,240 3,267 3,564 3,630 3,645 3,888 3,960 4,356 4,455 4,752 4,840 4,860 5,346 5,445 5,808 5,832 5,940 6,480 6,534 7,128 7,260 7,290 7,920 8,019 8,712 8,910 9,680 9,720 9,801 10,692 10,890 11,664 11,880 13,068 13,365 14,256 14,520 14,580 16,038 16,335 17,424 17,820 19,440 19,602 21,384 21,780 23,760 26,136 26,730 29,040 29,160 29,403 32,076 32,670 35,640 39,204 40,095 42,768 43,560 49,005 52,272 53,460 58,320 58,806 64,152 65,340 71,280 78,408 80,190 87,120 88,209 98,010 106,920 117,612 128,304 130,680 147,015 156,816 160,380 176,418 196,020 213,840 235,224 261,360 294,030 320,760 352,836 392,040 441,045 470,448 588,060 641,520 705,672 784,080 882,090 1,176,120 1,411,344 1,764,180 2,352,240 3,528,360 and 7,056,720, with no remainder.
Since 7,056,720 cannot be divided by just 1 and 7,056,720, it is not a prime number.