A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7175844 can be evenly divided by 1 2 3 4 6 9 12 13 18 19 26 27 36 38 39 52 54 57 76 78 108 114 117 156 171 228 234 247 269 342 351 468 494 513 538 684 702 741 807 988 1,026 1,076 1,404 1,482 1,614 2,052 2,223 2,421 2,964 3,228 3,497 4,446 4,842 5,111 6,669 6,994 7,263 8,892 9,684 10,222 10,491 13,338 13,988 14,526 15,333 20,444 20,982 26,676 29,052 30,666 31,473 41,964 45,999 61,332 62,946 66,443 91,998 94,419 125,892 132,886 137,997 183,996 188,838 199,329 265,772 275,994 377,676 398,658 551,988 597,987 797,316 1,195,974 1,793,961 2,391,948 3,587,922 and 7,175,844, with no remainder.
Since 7,175,844 cannot be divided by just 1 and 7,175,844, it is not a prime number.