The number 6,750,000 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 16 18 20 24 25 27 30 36 40 45 48 50 54 60 72 75 80 90 100 108 120 125 135 144 150 180 200 216 225 240 250 270 300 360 375 400 432 450 500 540 600 625 675 720 750 900 1,000 1,080 1,125 1,200 1,250 1,350 1,500 1,800 1,875 2,000 2,160 2,250 2,500 2,700 3,000 3,125 3,375 3,600 3,750 4,500 5,000 5,400 5,625 6,000 6,250 6,750 7,500 9,000 9,375 10,000 10,800 11,250 12,500 13,500 15,000 15,625 16,875 18,000 18,750 22,500 25,000 27,000 28,125 30,000 31,250 33,750 37,500 45,000 46,875 50,000 54,000 56,250 62,500 67,500 75,000 84,375 90,000 93,750 112,500 125,000 135,000 140,625 150,000 168,750 187,500 225,000 250,000 270,000 281,250 337,500 375,000 421,875 450,000 562,500 675,000 750,000 843,750 1,125,000 1,350,000 1,687,500 2,250,000 3,375,000 and 6,750,000, with no remainder.
Since 6,750,000 cannot be divided by just 1 and 6,750,000, it is a composite number.