A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8075808 can be evenly divided by 1 2 3 4 6 8 9 12 13 16 18 24 26 27 32 36 39 48 52 54 72 78 96 104 108 117 144 156 208 216 234 288 312 351 416 432 468 624 702 719 864 936 1,248 1,404 1,438 1,872 2,157 2,808 2,876 3,744 4,314 5,616 5,752 6,471 8,628 9,347 11,232 11,504 12,942 17,256 18,694 19,413 23,008 25,884 28,041 34,512 37,388 38,826 51,768 56,082 69,024 74,776 77,652 84,123 103,536 112,164 149,552 155,304 168,246 207,072 224,328 252,369 299,104 310,608 336,492 448,656 504,738 621,216 672,984 897,312 1,009,476 1,345,968 2,018,952 2,691,936 4,037,904 and 8,075,808, with no remainder.
Since 8,075,808 cannot be divided by just 1 and 8,075,808, it is not a prime number.