A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1282050 can be evenly divided by 1 2 3 5 6 7 9 10 11 14 15 18 21 22 25 30 33 35 37 42 45 50 55 63 66 70 74 75 77 90 99 105 110 111 126 150 154 165 175 185 198 210 222 225 231 259 275 315 330 333 350 370 385 407 450 462 495 518 525 550 555 630 666 693 770 777 814 825 925 990 1,050 1,110 1,155 1,221 1,295 1,386 1,554 1,575 1,650 1,665 1,850 1,925 2,035 2,310 2,331 2,442 2,475 2,590 2,775 2,849 3,150 3,330 3,465 3,663 3,850 3,885 4,070 4,662 4,950 5,550 5,698 5,775 6,105 6,475 6,930 7,326 7,770 8,325 8,547 10,175 11,550 11,655 12,210 12,950 14,245 16,650 17,094 17,325 18,315 19,425 20,350 23,310 25,641 28,490 30,525 34,650 36,630 38,850 42,735 51,282 58,275 61,050 71,225 85,470 91,575 116,550 128,205 142,450 183,150 213,675 256,410 427,350 641,025 and 1,282,050, with no remainder.
Since 1,282,050 cannot be divided by just 1 and 1,282,050, it is not a prime number.