The number 7,777,800 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 18 20 24 25 29 30 36 40 45 50 58 60 72 75 87 90 100 116 120 145 149 150 174 180 200 225 232 261 290 298 300 348 360 435 447 450 522 580 596 600 696 725 745 870 894 900 1,044 1,160 1,192 1,305 1,341 1,450 1,490 1,740 1,788 1,800 2,088 2,175 2,235 2,610 2,682 2,900 2,980 3,480 3,576 3,725 4,321 4,350 4,470 5,220 5,364 5,800 5,960 6,525 6,705 7,450 8,642 8,700 8,940 10,440 10,728 11,175 12,963 13,050 13,410 14,900 17,284 17,400 17,880 21,605 22,350 25,926 26,100 26,820 29,800 33,525 34,568 38,889 43,210 44,700 51,852 52,200 53,640 64,815 67,050 77,778 86,420 89,400 103,704 108,025 129,630 134,100 155,556 172,840 194,445 216,050 259,260 268,200 311,112 324,075 388,890 432,100 518,520 648,150 777,780 864,200 972,225 1,296,300 1,555,560 1,944,450 2,592,600 3,888,900 and 7,777,800, with no remainder.
Since 7,777,800 cannot be divided by just 1 and 7,777,800, it is a composite number.