A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2107404 can be evenly divided by 1 2 3 4 6 9 12 13 18 19 26 27 36 38 39 52 54 57 76 78 79 108 114 117 156 158 171 228 234 237 247 316 342 351 468 474 494 513 684 702 711 741 948 988 1,026 1,027 1,404 1,422 1,482 1,501 2,052 2,054 2,133 2,223 2,844 2,964 3,002 3,081 4,108 4,266 4,446 4,503 6,004 6,162 6,669 8,532 8,892 9,006 9,243 12,324 13,338 13,509 18,012 18,486 19,513 26,676 27,018 27,729 36,972 39,026 40,527 54,036 55,458 58,539 78,052 81,054 110,916 117,078 162,108 175,617 234,156 351,234 526,851 702,468 1,053,702 and 2,107,404, with no remainder.
Since 2,107,404 cannot be divided by just 1 and 2,107,404, it is not a prime number.