A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 5051112 can be evenly divided by 1 2 3 4 6 8 11 12 19 22 24 33 38 44 53 57 66 76 88 106 114 132 152 159 209 212 228 264 318 361 418 424 456 583 627 636 722 836 1,007 1,083 1,166 1,254 1,272 1,444 1,672 1,749 2,014 2,166 2,332 2,508 2,888 3,021 3,498 3,971 4,028 4,332 4,664 5,016 6,042 6,996 7,942 8,056 8,664 11,077 11,913 12,084 13,992 15,884 19,133 22,154 23,826 24,168 31,768 33,231 38,266 44,308 47,652 57,399 66,462 76,532 88,616 95,304 114,798 132,924 153,064 210,463 229,596 265,848 420,926 459,192 631,389 841,852 1,262,778 1,683,704 2,525,556 and 5,051,112, with no remainder.
Since 5,051,112 cannot be divided by just 1 and 5,051,112, it is not a prime number.