A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 9028500 can be evenly divided by 1 2 3 4 5 6 10 12 13 15 20 25 26 30 39 50 52 60 65 75 78 100 125 130 150 156 195 250 260 300 325 375 390 463 500 650 750 780 926 975 1,300 1,389 1,500 1,625 1,852 1,950 2,315 2,778 3,250 3,900 4,630 4,875 5,556 6,019 6,500 6,945 9,260 9,750 11,575 12,038 13,890 18,057 19,500 23,150 24,076 27,780 30,095 34,725 36,114 46,300 57,875 60,190 69,450 72,228 90,285 115,750 120,380 138,900 150,475 173,625 180,570 231,500 300,950 347,250 361,140 451,425 601,900 694,500 752,375 902,850 1,504,750 1,805,700 2,257,125 3,009,500 4,514,250 and 9,028,500, with no remainder.
Since 9,028,500 cannot be divided by just 1 and 9,028,500, it is not a prime number.