A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2250612 can be evenly divided by 1 2 3 4 6 7 9 12 13 14 18 21 26 27 28 36 39 42 52 54 63 78 84 91 108 117 126 156 182 189 229 234 252 273 351 364 378 458 468 546 687 702 756 819 916 1,092 1,374 1,404 1,603 1,638 2,061 2,457 2,748 2,977 3,206 3,276 4,122 4,809 4,914 5,954 6,183 6,412 8,244 8,931 9,618 9,828 11,908 12,366 14,427 17,862 19,236 20,839 24,732 26,793 28,854 35,724 41,678 43,281 53,586 57,708 62,517 80,379 83,356 86,562 107,172 125,034 160,758 173,124 187,551 250,068 321,516 375,102 562,653 750,204 1,125,306 and 2,250,612, with no remainder.
Since 2,250,612 cannot be divided by just 1 and 2,250,612, it is not a prime number.