A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3584280 can be evenly divided by 1 2 3 4 5 6 7 8 10 12 14 15 17 20 21 24 28 30 34 35 40 42 51 56 60 68 70 84 85 102 105 119 120 136 140 168 170 204 210 238 251 255 280 340 357 408 420 476 502 510 595 680 714 753 840 952 1,004 1,020 1,190 1,255 1,428 1,506 1,757 1,785 2,008 2,040 2,380 2,510 2,856 3,012 3,514 3,570 3,765 4,267 4,760 5,020 5,271 6,024 7,028 7,140 7,530 8,534 8,785 10,040 10,542 12,801 14,056 14,280 15,060 17,068 17,570 21,084 21,335 25,602 26,355 29,869 30,120 34,136 35,140 42,168 42,670 51,204 52,710 59,738 64,005 70,280 85,340 89,607 102,408 105,420 119,476 128,010 149,345 170,680 179,214 210,840 238,952 256,020 298,690 358,428 448,035 512,040 597,380 716,856 896,070 1,194,760 1,792,140 and 3,584,280, with no remainder.
Since 3,584,280 cannot be divided by just 1 and 3,584,280, it is not a prime number.