A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6125544 can be evenly divided by 1 2 3 4 6 8 9 12 18 23 24 27 36 46 54 69 72 81 92 108 137 138 162 184 207 216 243 274 276 324 411 414 486 548 552 621 648 822 828 972 1,096 1,233 1,242 1,644 1,656 1,863 1,944 2,466 2,484 3,151 3,288 3,699 3,726 4,932 4,968 5,589 6,302 7,398 7,452 9,453 9,864 11,097 11,178 12,604 14,796 14,904 18,906 22,194 22,356 25,208 28,359 29,592 33,291 37,812 44,388 44,712 56,718 66,582 75,624 85,077 88,776 113,436 133,164 170,154 226,872 255,231 266,328 340,308 510,462 680,616 765,693 1,020,924 1,531,386 2,041,848 3,062,772 and 6,125,544, with no remainder.
Since 6,125,544 cannot be divided by just 1 and 6,125,544, it is not a prime number.