A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 938196 can be evenly divided by 1 2 3 4 6 7 9 12 14 17 18 21 27 28 34 36 42 51 54 63 68 73 84 102 108 119 126 146 153 189 204 219 238 252 292 306 357 378 438 459 476 511 612 657 714 756 876 918 1,022 1,071 1,241 1,314 1,428 1,533 1,836 1,971 2,044 2,142 2,482 2,628 3,066 3,213 3,723 3,942 4,284 4,599 4,964 6,132 6,426 7,446 7,884 8,687 9,198 11,169 12,852 13,797 14,892 17,374 18,396 22,338 26,061 27,594 33,507 34,748 44,676 52,122 55,188 67,014 78,183 104,244 134,028 156,366 234,549 312,732 469,098 and 938,196, with no remainder.
Since 938,196 cannot be divided by just 1 and 938,196, it is not a prime number.