The number 512,820 can be evenly divided by 1 2 3 4 5 6 7 9 10 11 12 14 15 18 20 21 22 28 30 33 35 36 37 42 44 45 55 60 63 66 70 74 77 84 90 99 105 110 111 126 132 140 148 154 165 180 185 198 210 220 222 231 252 259 308 315 330 333 370 385 396 407 420 444 462 495 518 555 630 660 666 693 740 770 777 814 924 990 1,036 1,110 1,155 1,221 1,260 1,295 1,332 1,386 1,540 1,554 1,628 1,665 1,980 2,035 2,220 2,310 2,331 2,442 2,590 2,772 2,849 3,108 3,330 3,465 3,663 3,885 4,070 4,620 4,662 4,884 5,180 5,698 6,105 6,660 6,930 7,326 7,770 8,140 8,547 9,324 11,396 11,655 12,210 13,860 14,245 14,652 15,540 17,094 18,315 23,310 24,420 25,641 28,490 34,188 36,630 42,735 46,620 51,282 56,980 73,260 85,470 102,564 128,205 170,940 256,410 and 512,820, with no remainder.
Since 512,820 cannot be divided by just 1 and 512,820, it is a composite number.