The number 1,391,280 can be evenly divided by 1 2 3 4 5 6 8 10 11 12 15 16 17 20 22 24 30 31 33 34 40 44 48 51 55 60 62 66 68 80 85 88 93 102 110 120 124 132 136 155 165 170 176 186 187 204 220 240 248 255 264 272 310 330 340 341 372 374 408 440 465 496 510 527 528 561 620 660 680 682 744 748 816 880 930 935 1,020 1,023 1,054 1,122 1,240 1,320 1,360 1,364 1,488 1,496 1,581 1,705 1,860 1,870 2,040 2,046 2,108 2,244 2,480 2,635 2,640 2,728 2,805 2,992 3,162 3,410 3,720 3,740 4,080 4,092 4,216 4,488 5,115 5,270 5,456 5,610 5,797 6,324 6,820 7,440 7,480 7,905 8,184 8,432 8,976 10,230 10,540 11,220 11,594 12,648 13,640 14,960 15,810 16,368 17,391 20,460 21,080 22,440 23,188 25,296 27,280 28,985 31,620 34,782 40,920 42,160 44,880 46,376 57,970 63,240 69,564 81,840 86,955 92,752 115,940 126,480 139,128 173,910 231,880 278,256 347,820 463,760 695,640 and 1,391,280, with no remainder.
Since 1,391,280 cannot be divided by just 1 and 1,391,280, it is a composite number.