A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7681080 can be evenly divided by 1 2 3 4 5 6 8 10 11 12 15 20 22 23 24 30 33 40 44 46 55 60 66 69 88 92 110 115 120 121 132 138 165 184 220 230 242 253 264 276 330 345 363 440 460 484 506 529 552 605 660 690 726 759 920 968 1,012 1,058 1,210 1,265 1,320 1,380 1,452 1,518 1,587 1,815 2,024 2,116 2,420 2,530 2,645 2,760 2,783 2,904 3,036 3,174 3,630 3,795 4,232 4,840 5,060 5,290 5,566 5,819 6,072 6,348 7,260 7,590 7,935 8,349 10,120 10,580 11,132 11,638 12,696 13,915 14,520 15,180 15,870 16,698 17,457 21,160 22,264 23,276 27,830 29,095 30,360 31,740 33,396 34,914 41,745 46,552 55,660 58,190 63,480 64,009 66,792 69,828 83,490 87,285 111,320 116,380 128,018 139,656 166,980 174,570 192,027 232,760 256,036 320,045 333,960 349,140 384,054 512,072 640,090 698,280 768,108 960,135 1,280,180 1,536,216 1,920,270 2,560,360 3,840,540 and 7,681,080, with no remainder.
Since 7,681,080 cannot be divided by just 1 and 7,681,080, it is not a prime number.