A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8075000 can be evenly divided by 1 2 4 5 8 10 17 19 20 25 34 38 40 50 68 76 85 95 100 125 136 152 170 190 200 250 323 340 380 425 475 500 625 646 680 760 850 950 1,000 1,250 1,292 1,615 1,700 1,900 2,125 2,375 2,500 2,584 3,125 3,230 3,400 3,800 4,250 4,750 5,000 6,250 6,460 8,075 8,500 9,500 10,625 11,875 12,500 12,920 16,150 17,000 19,000 21,250 23,750 25,000 32,300 40,375 42,500 47,500 53,125 59,375 64,600 80,750 85,000 95,000 106,250 118,750 161,500 201,875 212,500 237,500 323,000 403,750 425,000 475,000 807,500 1,009,375 1,615,000 2,018,750 4,037,500 and 8,075,000, with no remainder.
Since 8,075,000 cannot be divided by just 1 and 8,075,000, it is not a prime number.