A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2748960 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 16 18 20 23 24 30 32 36 40 45 46 48 60 69 72 80 83 90 92 96 115 120 138 144 160 166 180 184 207 230 240 249 276 288 332 345 360 368 414 415 460 480 498 552 664 690 720 736 747 828 830 920 996 1,035 1,104 1,245 1,328 1,380 1,440 1,494 1,656 1,660 1,840 1,909 1,992 2,070 2,208 2,490 2,656 2,760 2,988 3,312 3,320 3,680 3,735 3,818 3,984 4,140 4,980 5,520 5,727 5,976 6,624 6,640 7,470 7,636 7,968 8,280 9,545 9,960 11,040 11,454 11,952 13,280 14,940 15,272 16,560 17,181 19,090 19,920 22,908 23,904 28,635 29,880 30,544 33,120 34,362 38,180 39,840 45,816 57,270 59,760 61,088 68,724 76,360 85,905 91,632 114,540 119,520 137,448 152,720 171,810 183,264 229,080 274,896 305,440 343,620 458,160 549,792 687,240 916,320 1,374,480 and 2,748,960, with no remainder.
Since 2,748,960 cannot be divided by just 1 and 2,748,960, it is not a prime number.