The number 551,880 can be evenly divided by 1 2 3 4 5 6 7 8 9 10 12 14 15 18 20 21 24 27 28 30 35 36 40 42 45 54 56 60 63 70 72 73 84 90 105 108 120 126 135 140 146 168 180 189 210 216 219 252 270 280 292 315 360 365 378 420 438 504 511 540 584 630 657 730 756 840 876 945 1,022 1,080 1,095 1,260 1,314 1,460 1,512 1,533 1,752 1,890 1,971 2,044 2,190 2,520 2,555 2,628 2,920 3,066 3,285 3,780 3,942 4,088 4,380 4,599 5,110 5,256 6,132 6,570 7,560 7,665 7,884 8,760 9,198 9,855 10,220 12,264 13,140 13,797 15,330 15,768 18,396 19,710 20,440 22,995 26,280 27,594 30,660 36,792 39,420 45,990 55,188 61,320 68,985 78,840 91,980 110,376 137,970 183,960 275,940 and 551,880, with no remainder.
Since 551,880 cannot be divided by just 1 and 551,880, it is a composite number.