A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7627500 can be evenly divided by 1 2 3 4 5 6 9 10 12 15 18 20 25 27 30 36 45 50 54 60 75 90 100 108 113 125 135 150 180 225 226 250 270 300 339 375 450 452 500 540 565 625 675 678 750 900 1,017 1,125 1,130 1,250 1,350 1,356 1,500 1,695 1,875 2,034 2,250 2,260 2,500 2,700 2,825 3,051 3,375 3,390 3,750 4,068 4,500 5,085 5,625 5,650 6,102 6,750 6,780 7,500 8,475 10,170 11,250 11,300 12,204 13,500 14,125 15,255 16,875 16,950 20,340 22,500 25,425 28,250 30,510 33,750 33,900 42,375 50,850 56,500 61,020 67,500 70,625 76,275 84,750 101,700 127,125 141,250 152,550 169,500 211,875 254,250 282,500 305,100 381,375 423,750 508,500 635,625 762,750 847,500 1,271,250 1,525,500 1,906,875 2,542,500 3,813,750 and 7,627,500, with no remainder.
Since 7,627,500 cannot be divided by just 1 and 7,627,500, it is not a prime number.