A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6723486 can be evenly divided by 1 2 3 6 7 9 11 14 18 21 22 27 33 42 49 54 63 66 77 81 98 99 121 126 147 154 162 189 198 231 242 294 297 343 363 378 441 462 539 567 594 686 693 726 847 882 891 1,029 1,078 1,089 1,134 1,323 1,386 1,617 1,694 1,782 2,058 2,079 2,178 2,541 2,646 3,087 3,234 3,267 3,773 3,969 4,158 4,851 5,082 5,929 6,174 6,237 6,534 7,546 7,623 7,938 9,261 9,702 9,801 11,319 11,858 12,474 14,553 15,246 17,787 18,522 19,602 22,638 22,869 27,783 29,106 33,957 35,574 41,503 43,659 45,738 53,361 55,566 67,914 68,607 83,006 87,318 101,871 106,722 124,509 137,214 160,083 203,742 249,018 305,613 320,166 373,527 480,249 611,226 747,054 960,498 1,120,581 2,241,162 3,361,743 and 6,723,486, with no remainder.
Since 6,723,486 cannot be divided by just 1 and 6,723,486, it is not a prime number.