A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6757860 can be evenly divided by 1 2 3 4 5 6 10 12 15 20 23 30 46 59 60 69 83 92 115 118 138 166 177 230 236 249 276 295 332 345 354 415 460 498 590 690 708 830 885 996 1,180 1,245 1,357 1,380 1,660 1,770 1,909 2,490 2,714 3,540 3,818 4,071 4,897 4,980 5,428 5,727 6,785 7,636 8,142 9,545 9,794 11,454 13,570 14,691 16,284 19,090 19,588 20,355 22,908 24,485 27,140 28,635 29,382 38,180 40,710 48,970 57,270 58,764 73,455 81,420 97,940 112,631 114,540 146,910 225,262 293,820 337,893 450,524 563,155 675,786 1,126,310 1,351,572 1,689,465 2,252,620 3,378,930 and 6,757,860, with no remainder.
Since 6,757,860 cannot be divided by just 1 and 6,757,860, it is not a prime number.