A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 222768 can be evenly divided by 1 2 3 4 6 7 8 9 12 13 14 16 17 18 21 24 26 28 34 36 39 42 48 51 52 56 63 68 72 78 84 91 102 104 112 117 119 126 136 144 153 156 168 182 204 208 221 234 238 252 272 273 306 312 336 357 364 408 442 468 476 504 546 612 624 663 714 728 816 819 884 936 952 1,008 1,071 1,092 1,224 1,326 1,428 1,456 1,547 1,638 1,768 1,872 1,904 1,989 2,142 2,184 2,448 2,652 2,856 3,094 3,276 3,536 3,978 4,284 4,368 4,641 5,304 5,712 6,188 6,552 7,956 8,568 9,282 10,608 12,376 13,104 13,923 15,912 17,136 18,564 24,752 27,846 31,824 37,128 55,692 74,256 111,384 and 222,768, with no remainder.
Since 222,768 cannot be divided by just 1 and 222,768, it is not a prime number.