A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6271272 can be evenly divided by 1 2 3 4 6 7 8 9 12 14 18 21 23 24 28 36 42 46 56 63 69 72 84 92 126 138 161 168 184 207 252 276 322 414 483 504 541 552 644 828 966 1,082 1,288 1,449 1,623 1,656 1,932 2,164 2,898 3,246 3,787 3,864 4,328 4,869 5,796 6,492 7,574 9,738 11,361 11,592 12,443 12,984 15,148 19,476 22,722 24,886 30,296 34,083 37,329 38,952 45,444 49,772 68,166 74,658 87,101 90,888 99,544 111,987 136,332 149,316 174,202 223,974 261,303 272,664 298,632 348,404 447,948 522,606 696,808 783,909 895,896 1,045,212 1,567,818 2,090,424 3,135,636 and 6,271,272, with no remainder.
Since 6,271,272 cannot be divided by just 1 and 6,271,272, it is not a prime number.