A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2734560 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 16 18 20 24 27 30 32 36 40 45 48 54 60 72 80 81 90 96 108 120 135 144 160 162 180 211 216 240 270 288 324 360 405 422 432 480 540 633 648 720 810 844 864 1,055 1,080 1,266 1,296 1,440 1,620 1,688 1,899 2,110 2,160 2,532 2,592 3,165 3,240 3,376 3,798 4,220 4,320 5,064 5,697 6,330 6,480 6,752 7,596 8,440 9,495 10,128 11,394 12,660 12,960 15,192 16,880 17,091 18,990 20,256 22,788 25,320 28,485 30,384 33,760 34,182 37,980 45,576 50,640 56,970 60,768 68,364 75,960 85,455 91,152 101,280 113,940 136,728 151,920 170,910 182,304 227,880 273,456 303,840 341,820 455,760 546,912 683,640 911,520 1,367,280 and 2,734,560, with no remainder.
Since 2,734,560 cannot be divided by just 1 and 2,734,560, it is not a prime number.