A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 5760720 can be evenly divided by 1 2 3 4 5 6 7 8 9 10 12 14 15 16 18 20 21 24 27 28 30 35 36 40 42 45 48 54 56 60 63 70 72 80 81 84 90 105 108 112 120 126 127 135 140 144 162 168 180 189 210 216 240 252 254 270 280 315 324 336 360 378 381 405 420 432 504 508 540 560 567 630 635 648 720 756 762 810 840 889 945 1,008 1,016 1,080 1,134 1,143 1,260 1,270 1,296 1,512 1,524 1,620 1,680 1,778 1,890 1,905 2,032 2,160 2,268 2,286 2,520 2,540 2,667 2,835 3,024 3,048 3,240 3,429 3,556 3,780 3,810 4,445 4,536 4,572 5,040 5,080 5,334 5,670 5,715 6,096 6,480 6,858 7,112 7,560 7,620 8,001 8,890 9,072 9,144 10,160 10,287 10,668 11,340 11,430 13,335 13,716 14,224 15,120 15,240 16,002 17,145 17,780 18,288 20,574 21,336 22,680 22,860 24,003 26,670 27,432 30,480 32,004 34,290 35,560 40,005 41,148 42,672 45,360 45,720 48,006 51,435 53,340 54,864 64,008 68,580 71,120 72,009 80,010 82,296 91,440 96,012 102,870 106,680 120,015 128,016 137,160 144,018 160,020 164,592 192,024 205,740 213,360 240,030 274,320 288,036 320,040 360,045 384,048 411,480 480,060 576,072 640,080 720,090 822,960 960,120 1,152,144 1,440,180 1,920,240 2,880,360 and 5,760,720, with no remainder.
Since 5,760,720 cannot be divided by just 1 and 5,760,720, it is not a prime number.