A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2231424 can be evenly divided by 1 2 3 4 6 8 9 12 13 16 18 24 26 32 36 39 48 52 64 72 78 96 104 117 128 144 149 156 192 208 234 288 298 312 384 416 447 468 576 596 624 832 894 936 1,152 1,192 1,248 1,341 1,664 1,788 1,872 1,937 2,384 2,496 2,682 3,576 3,744 3,874 4,768 4,992 5,364 5,811 7,152 7,488 7,748 9,536 10,728 11,622 14,304 14,976 15,496 17,433 19,072 21,456 23,244 28,608 30,992 34,866 42,912 46,488 57,216 61,984 69,732 85,824 92,976 123,968 139,464 171,648 185,952 247,936 278,928 371,904 557,856 743,808 1,115,712 and 2,231,424, with no remainder.
Since 2,231,424 cannot be divided by just 1 and 2,231,424, it is not a prime number.