A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2426970 can be evenly divided by 1 2 3 5 6 7 10 13 14 15 21 26 30 35 39 42 49 65 70 78 91 98 105 127 130 147 182 195 210 245 254 273 294 381 390 455 490 546 635 637 735 762 889 910 1,270 1,274 1,365 1,470 1,651 1,778 1,905 1,911 2,667 2,730 3,185 3,302 3,810 3,822 4,445 4,953 5,334 6,223 6,370 8,255 8,890 9,555 9,906 11,557 12,446 13,335 16,510 18,669 19,110 23,114 24,765 26,670 31,115 34,671 37,338 49,530 57,785 62,230 69,342 80,899 93,345 115,570 161,798 173,355 186,690 242,697 346,710 404,495 485,394 808,990 1,213,485 and 2,426,970, with no remainder.
Since 2,426,970 cannot be divided by just 1 and 2,426,970, it is not a prime number.