A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7527800 can be evenly divided by 1 2 4 5 7 8 10 14 19 20 25 28 35 38 40 50 56 70 76 95 100 133 140 152 175 190 200 266 280 283 350 380 475 532 566 665 700 760 950 1,064 1,132 1,330 1,400 1,415 1,900 1,981 2,264 2,660 2,830 3,325 3,800 3,962 5,320 5,377 5,660 6,650 7,075 7,924 9,905 10,754 11,320 13,300 14,150 15,848 19,810 21,508 26,600 26,885 28,300 37,639 39,620 43,016 49,525 53,770 56,600 75,278 79,240 99,050 107,540 134,425 150,556 188,195 198,100 215,080 268,850 301,112 376,390 396,200 537,700 752,780 940,975 1,075,400 1,505,560 1,881,950 3,763,900 and 7,527,800, with no remainder.
Since 7,527,800 cannot be divided by just 1 and 7,527,800, it is not a prime number.