A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2885120 can be evenly divided by 1 2 4 5 7 8 10 14 16 20 23 28 32 35 40 46 49 56 64 70 80 92 98 112 115 128 140 160 161 184 196 224 230 245 256 280 320 322 368 392 448 460 490 512 560 640 644 736 784 805 896 920 980 1,120 1,127 1,280 1,288 1,472 1,568 1,610 1,792 1,840 1,960 2,240 2,254 2,560 2,576 2,944 3,136 3,220 3,584 3,680 3,920 4,480 4,508 5,152 5,635 5,888 6,272 6,440 7,360 7,840 8,960 9,016 10,304 11,270 11,776 12,544 12,880 14,720 15,680 17,920 18,032 20,608 22,540 25,088 25,760 29,440 31,360 36,064 41,216 45,080 51,520 58,880 62,720 72,128 82,432 90,160 103,040 125,440 144,256 180,320 206,080 288,512 360,640 412,160 577,024 721,280 1,442,560 and 2,885,120, with no remainder.
Since 2,885,120 cannot be divided by just 1 and 2,885,120, it is not a prime number.