A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2506350 can be evenly divided by 1 2 3 5 6 7 10 11 14 15 21 22 25 30 31 33 35 42 49 50 55 62 66 70 75 77 93 98 105 110 147 150 154 155 165 175 186 210 217 231 245 275 294 310 330 341 350 385 434 462 465 490 525 539 550 651 682 735 770 775 825 930 1,023 1,050 1,078 1,085 1,155 1,225 1,302 1,470 1,519 1,550 1,617 1,650 1,705 1,925 2,046 2,170 2,310 2,325 2,387 2,450 2,695 3,038 3,234 3,255 3,410 3,675 3,850 4,557 4,650 4,774 5,115 5,390 5,425 5,775 6,510 7,161 7,350 7,595 8,085 8,525 9,114 10,230 10,850 11,550 11,935 13,475 14,322 15,190 16,170 16,275 16,709 17,050 22,785 23,870 25,575 26,950 32,550 33,418 35,805 37,975 40,425 45,570 50,127 51,150 59,675 71,610 75,950 80,850 83,545 100,254 113,925 119,350 167,090 179,025 227,850 250,635 358,050 417,725 501,270 835,450 1,253,175 and 2,506,350, with no remainder.
Since 2,506,350 cannot be divided by just 1 and 2,506,350, it is not a prime number.