A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1165104 can be evenly divided by 1 2 3 4 6 8 9 12 16 18 24 27 29 31 36 48 54 58 62 72 81 87 93 108 116 124 144 162 174 186 216 232 248 261 279 324 348 372 432 464 496 522 558 648 696 744 783 837 899 1,044 1,116 1,296 1,392 1,488 1,566 1,674 1,798 2,088 2,232 2,349 2,511 2,697 3,132 3,348 3,596 4,176 4,464 4,698 5,022 5,394 6,264 6,696 7,192 8,091 9,396 10,044 10,788 12,528 13,392 14,384 16,182 18,792 20,088 21,576 24,273 32,364 37,584 40,176 43,152 48,546 64,728 72,819 97,092 129,456 145,638 194,184 291,276 388,368 582,552 and 1,165,104, with no remainder.
Since 1,165,104 cannot be divided by just 1 and 1,165,104, it is not a prime number.