A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3776760 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 13 15 18 20 24 26 27 30 36 39 40 45 52 54 60 65 72 78 90 104 108 117 120 130 135 156 180 195 216 234 260 269 270 312 351 360 390 468 520 538 540 585 702 780 807 936 1,076 1,080 1,170 1,345 1,404 1,560 1,614 1,755 2,152 2,340 2,421 2,690 2,808 3,228 3,497 3,510 4,035 4,680 4,842 5,380 6,456 6,994 7,020 7,263 8,070 9,684 10,491 10,760 12,105 13,988 14,040 14,526 16,140 17,485 19,368 20,982 24,210 27,976 29,052 31,473 32,280 34,970 36,315 41,964 48,420 52,455 58,104 62,946 69,940 72,630 83,928 94,419 96,840 104,910 125,892 139,880 145,260 157,365 188,838 209,820 251,784 290,520 314,730 377,676 419,640 472,095 629,460 755,352 944,190 1,258,920 1,888,380 and 3,776,760, with no remainder.
Since 3,776,760 cannot be divided by just 1 and 3,776,760, it is not a prime number.