A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1181180 can be evenly divided by 1 2 4 5 7 10 11 13 14 20 22 26 28 35 44 52 55 59 65 70 77 91 110 118 130 140 143 154 182 220 236 260 286 295 308 364 385 413 455 572 590 649 715 767 770 826 910 1,001 1,180 1,298 1,430 1,534 1,540 1,652 1,820 2,002 2,065 2,596 2,860 3,068 3,245 3,835 4,004 4,130 4,543 5,005 5,369 6,490 7,670 8,260 8,437 9,086 10,010 10,738 12,980 15,340 16,874 18,172 20,020 21,476 22,715 26,845 33,748 42,185 45,430 53,690 59,059 84,370 90,860 107,380 118,118 168,740 236,236 295,295 590,590 and 1,181,180, with no remainder.
Since 1,181,180 cannot be divided by just 1 and 1,181,180, it is not a prime number.