A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2801106 can be evenly divided by 1 2 3 6 7 9 11 14 18 21 22 33 42 43 47 63 66 77 86 94 99 126 129 141 154 198 231 258 282 301 329 387 423 462 473 517 602 658 693 774 846 903 946 987 1,034 1,386 1,419 1,551 1,806 1,974 2,021 2,709 2,838 2,961 3,102 3,311 3,619 4,042 4,257 4,653 5,418 5,922 6,063 6,622 7,238 8,514 9,306 9,933 10,857 12,126 14,147 18,189 19,866 21,714 22,231 28,294 29,799 32,571 36,378 42,441 44,462 59,598 65,142 66,693 84,882 127,323 133,386 155,617 200,079 254,646 311,234 400,158 466,851 933,702 1,400,553 and 2,801,106, with no remainder.
Since 2,801,106 cannot be divided by just 1 and 2,801,106, it is not a prime number.