The number 5,257,728 can be evenly divided by 1 2 3 4 6 7 8 9 12 14 16 18 21 24 28 32 36 42 48 56 63 64 72 84 96 112 126 128 144 163 168 192 224 252 256 288 326 336 384 448 489 504 512 576 652 672 768 896 978 1,008 1,141 1,152 1,304 1,344 1,467 1,536 1,792 1,956 2,016 2,282 2,304 2,608 2,688 2,934 3,423 3,584 3,912 4,032 4,564 4,608 5,216 5,376 5,868 6,846 7,824 8,064 9,128 10,269 10,432 10,752 11,736 13,692 15,648 16,128 18,256 20,538 20,864 23,472 27,384 31,296 32,256 36,512 41,076 41,728 46,944 54,768 62,592 73,024 82,152 83,456 93,888 109,536 125,184 146,048 164,304 187,776 219,072 250,368 292,096 328,608 375,552 438,144 584,192 657,216 751,104 876,288 1,314,432 1,752,576 2,628,864 and 5,257,728, with no remainder.
Since 5,257,728 cannot be divided by just 1 and 5,257,728, it is a composite number.