A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2677860 can be evenly divided by 1 2 3 4 5 6 9 10 12 15 18 19 20 27 29 30 36 38 45 54 57 58 60 76 81 87 90 95 108 114 116 135 145 162 171 174 180 190 228 243 261 270 285 290 324 342 348 380 405 435 486 513 522 540 551 570 580 684 783 810 855 870 972 1,026 1,044 1,102 1,140 1,215 1,305 1,539 1,566 1,620 1,653 1,710 1,740 2,052 2,204 2,349 2,430 2,565 2,610 2,755 3,078 3,132 3,306 3,420 3,915 4,617 4,698 4,860 4,959 5,130 5,220 5,510 6,156 6,612 7,047 7,695 7,830 8,265 9,234 9,396 9,918 10,260 11,020 11,745 14,094 14,877 15,390 15,660 16,530 18,468 19,836 23,085 23,490 24,795 28,188 29,754 30,780 33,060 35,235 44,631 46,170 46,980 49,590 59,508 70,470 74,385 89,262 92,340 99,180 133,893 140,940 148,770 178,524 223,155 267,786 297,540 446,310 535,572 669,465 892,620 1,338,930 and 2,677,860, with no remainder.
Since 2,677,860 cannot be divided by just 1 and 2,677,860, it is not a prime number.