A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2018280 can be evenly divided by 1 2 3 4 5 6 8 10 11 12 15 20 22 24 30 33 40 44 55 60 66 88 110 120 121 132 139 165 220 242 264 278 330 363 417 440 484 556 605 660 695 726 834 968 1,112 1,210 1,320 1,390 1,452 1,529 1,668 1,815 2,085 2,420 2,780 2,904 3,058 3,336 3,630 4,170 4,587 4,840 5,560 6,116 7,260 7,645 8,340 9,174 12,232 14,520 15,290 16,680 16,819 18,348 22,935 30,580 33,638 36,696 45,870 50,457 61,160 67,276 84,095 91,740 100,914 134,552 168,190 183,480 201,828 252,285 336,380 403,656 504,570 672,760 1,009,140 and 2,018,280, with no remainder.
Since 2,018,280 cannot be divided by just 1 and 2,018,280, it is not a prime number.