A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1200192 can be evenly divided by 1 2 3 4 6 7 8 12 14 16 19 21 24 28 32 38 42 47 48 56 57 64 76 84 94 96 112 114 133 141 152 168 188 192 224 228 266 282 304 329 336 376 399 448 456 532 564 608 658 672 752 798 893 912 987 1,064 1,128 1,216 1,316 1,344 1,504 1,596 1,786 1,824 1,974 2,128 2,256 2,632 2,679 3,008 3,192 3,572 3,648 3,948 4,256 4,512 5,264 5,358 6,251 6,384 7,144 7,896 8,512 9,024 10,528 10,716 12,502 12,768 14,288 15,792 18,753 21,056 21,432 25,004 25,536 28,576 31,584 37,506 42,864 50,008 57,152 63,168 75,012 85,728 100,016 150,024 171,456 200,032 300,048 400,064 600,096 and 1,200,192, with no remainder.
Since 1,200,192 cannot be divided by just 1 and 1,200,192, it is not a prime number.