A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7367256 can be evenly divided by 1 2 3 4 6 8 9 12 13 17 18 24 26 34 36 39 51 52 68 72 78 102 104 117 136 153 156 204 221 234 306 312 408 442 463 468 612 663 884 926 936 1,224 1,326 1,389 1,768 1,852 1,989 2,652 2,778 3,704 3,978 4,167 5,304 5,556 6,019 7,871 7,956 8,334 11,112 12,038 15,742 15,912 16,668 18,057 23,613 24,076 31,484 33,336 36,114 47,226 48,152 54,171 62,968 70,839 72,228 94,452 102,323 108,342 141,678 144,456 188,904 204,646 216,684 283,356 306,969 409,292 433,368 566,712 613,938 818,584 920,907 1,227,876 1,841,814 2,455,752 3,683,628 and 7,367,256, with no remainder.
Since 7,367,256 cannot be divided by just 1 and 7,367,256, it is not a prime number.