The number 820,260 can be evenly divided by 1 2 3 4 5 6 7 9 10 12 14 15 18 20 21 27 28 30 31 35 36 42 45 49 54 60 62 63 70 84 90 93 98 105 108 124 126 135 140 147 155 180 186 189 196 210 217 245 252 270 279 294 310 315 372 378 420 434 441 465 490 540 558 588 620 630 651 735 756 837 868 882 930 945 980 1,085 1,116 1,260 1,302 1,323 1,395 1,470 1,519 1,674 1,764 1,860 1,890 1,953 2,170 2,205 2,604 2,646 2,790 2,940 3,038 3,255 3,348 3,780 3,906 4,185 4,340 4,410 4,557 5,292 5,580 5,859 6,076 6,510 6,615 7,595 7,812 8,370 8,820 9,114 9,765 11,718 13,020 13,230 13,671 15,190 16,740 18,228 19,530 22,785 23,436 26,460 27,342 29,295 30,380 39,060 41,013 45,570 54,684 58,590 68,355 82,026 91,140 117,180 136,710 164,052 205,065 273,420 410,130 and 820,260, with no remainder.
Since 820,260 cannot be divided by just 1 and 820,260, it is a composite number.