A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2762208 can be evenly divided by 1 2 3 4 6 8 9 12 16 18 23 24 27 32 36 46 48 54 69 72 92 96 108 138 139 144 184 207 216 276 278 288 368 414 417 432 552 556 621 736 828 834 864 1,104 1,112 1,242 1,251 1,656 1,668 2,208 2,224 2,484 2,502 3,197 3,312 3,336 3,753 4,448 4,968 5,004 6,394 6,624 6,672 7,506 9,591 9,936 10,008 12,788 13,344 15,012 19,182 19,872 20,016 25,576 28,773 30,024 38,364 40,032 51,152 57,546 60,048 76,728 86,319 102,304 115,092 120,096 153,456 172,638 230,184 306,912 345,276 460,368 690,552 920,736 1,381,104 and 2,762,208, with no remainder.
Since 2,762,208 cannot be divided by just 1 and 2,762,208, it is not a prime number.