A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3776850 can be evenly divided by 1 2 3 5 6 7 9 10 11 14 15 18 21 22 25 30 33 35 42 45 50 55 63 66 70 75 77 90 99 105 109 110 126 150 154 165 175 198 210 218 225 231 275 315 327 330 350 385 450 462 495 525 545 550 630 654 693 763 770 825 981 990 1,050 1,090 1,155 1,199 1,386 1,526 1,575 1,635 1,650 1,925 1,962 2,289 2,310 2,398 2,475 2,725 3,150 3,270 3,465 3,597 3,815 3,850 4,578 4,905 4,950 5,450 5,775 5,995 6,867 6,930 7,194 7,630 8,175 8,393 9,810 10,791 11,445 11,550 11,990 13,734 16,350 16,786 17,325 17,985 19,075 21,582 22,890 24,525 25,179 29,975 34,335 34,650 35,970 38,150 41,965 49,050 50,358 53,955 57,225 59,950 68,670 75,537 83,930 89,925 107,910 114,450 125,895 151,074 171,675 179,850 209,825 251,790 269,775 343,350 377,685 419,650 539,550 629,475 755,370 1,258,950 1,888,425 and 3,776,850, with no remainder.
Since 3,776,850 cannot be divided by just 1 and 3,776,850, it is not a prime number.