A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8039232 can be evenly divided by 1 2 3 4 6 8 9 12 16 17 18 24 32 34 36 48 51 64 68 72 96 102 136 144 153 192 204 272 288 306 408 544 576 612 816 821 1,088 1,224 1,632 1,642 2,448 2,463 3,264 3,284 4,896 4,926 6,568 7,389 9,792 9,852 13,136 13,957 14,778 19,704 26,272 27,914 29,556 39,408 41,871 52,544 55,828 59,112 78,816 83,742 111,656 118,224 125,613 157,632 167,484 223,312 236,448 251,226 334,968 446,624 472,896 502,452 669,936 893,248 1,004,904 1,339,872 2,009,808 2,679,744 4,019,616 and 8,039,232, with no remainder.
Since 8,039,232 cannot be divided by just 1 and 8,039,232, it is not a prime number.