A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3650850 can be evenly divided by 1 2 3 5 6 7 9 10 14 15 18 19 21 25 30 35 38 42 45 50 57 61 63 70 75 90 95 105 114 122 126 133 150 171 175 183 190 210 225 266 285 305 315 342 350 366 399 427 450 475 525 549 570 610 630 665 798 854 855 915 950 1,050 1,098 1,159 1,197 1,281 1,330 1,425 1,525 1,575 1,710 1,830 1,995 2,135 2,318 2,394 2,562 2,745 2,850 3,050 3,150 3,325 3,477 3,843 3,990 4,270 4,275 4,575 5,490 5,795 5,985 6,405 6,650 6,954 7,686 8,113 8,550 9,150 9,975 10,431 10,675 11,590 11,970 12,810 13,725 16,226 17,385 19,215 19,950 20,862 21,350 24,339 27,450 28,975 29,925 32,025 34,770 38,430 40,565 48,678 52,155 57,950 59,850 64,050 73,017 81,130 86,925 96,075 104,310 121,695 146,034 173,850 192,150 202,825 243,390 260,775 365,085 405,650 521,550 608,475 730,170 1,216,950 1,825,425 and 3,650,850, with no remainder.
Since 3,650,850 cannot be divided by just 1 and 3,650,850, it is not a prime number.