The number 584,640 can be evenly divided by 1 2 3 4 5 6 7 8 9 10 12 14 15 16 18 20 21 24 28 29 30 32 35 36 40 42 45 48 56 58 60 63 64 70 72 80 84 87 90 96 105 112 116 120 126 140 144 145 160 168 174 180 192 203 210 224 232 240 252 261 280 288 290 315 320 336 348 360 406 420 435 448 464 480 504 522 560 576 580 609 630 672 696 720 812 840 870 928 960 1,008 1,015 1,044 1,120 1,160 1,218 1,260 1,305 1,344 1,392 1,440 1,624 1,680 1,740 1,827 1,856 2,016 2,030 2,088 2,240 2,320 2,436 2,520 2,610 2,784 2,880 3,045 3,248 3,360 3,480 3,654 4,032 4,060 4,176 4,640 4,872 5,040 5,220 5,568 6,090 6,496 6,720 6,960 7,308 8,120 8,352 9,135 9,280 9,744 10,080 10,440 12,180 12,992 13,920 14,616 16,240 16,704 18,270 19,488 20,160 20,880 24,360 27,840 29,232 32,480 36,540 38,976 41,760 48,720 58,464 64,960 73,080 83,520 97,440 116,928 146,160 194,880 292,320 and 584,640, with no remainder.
Since 584,640 cannot be divided by just 1 and 584,640, it is a composite number.