A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3305250 can be evenly divided by 1 2 3 5 6 9 10 13 15 18 25 26 30 39 45 50 65 75 78 90 113 117 125 130 150 195 225 226 234 250 325 339 375 390 450 565 585 650 678 750 975 1,017 1,125 1,130 1,170 1,469 1,625 1,695 1,950 2,034 2,250 2,825 2,925 2,938 3,250 3,390 4,407 4,875 5,085 5,650 5,850 7,345 8,475 8,814 9,750 10,170 13,221 14,125 14,625 14,690 16,950 22,035 25,425 26,442 28,250 29,250 36,725 42,375 44,070 50,850 66,105 73,450 84,750 110,175 127,125 132,210 183,625 220,350 254,250 330,525 367,250 550,875 661,050 1,101,750 1,652,625 and 3,305,250, with no remainder.
Since 3,305,250 cannot be divided by just 1 and 3,305,250, it is not a prime number.