A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1136460 can be evenly divided by 1 2 3 4 5 6 10 12 13 15 20 26 30 31 39 47 52 60 62 65 78 93 94 124 130 141 155 156 186 188 195 235 260 282 310 372 390 403 465 470 564 611 620 705 780 806 930 940 1,209 1,222 1,410 1,457 1,612 1,833 1,860 2,015 2,418 2,444 2,820 2,914 3,055 3,666 4,030 4,371 4,836 5,828 6,045 6,110 7,285 7,332 8,060 8,742 9,165 12,090 12,220 14,570 17,484 18,330 18,941 21,855 24,180 29,140 36,660 37,882 43,710 56,823 75,764 87,420 94,705 113,646 189,410 227,292 284,115 378,820 568,230 and 1,136,460, with no remainder.
Since 1,136,460 cannot be divided by just 1 and 1,136,460, it is not a prime number.