A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1211232 can be evenly divided by 1 2 3 4 6 8 11 12 16 22 24 31 32 33 37 44 48 62 66 74 88 93 96 111 124 132 148 176 186 222 248 264 296 341 352 372 407 444 496 528 592 682 744 814 888 992 1,023 1,056 1,147 1,184 1,221 1,364 1,488 1,628 1,776 2,046 2,294 2,442 2,728 2,976 3,256 3,441 3,552 4,092 4,588 4,884 5,456 6,512 6,882 8,184 9,176 9,768 10,912 12,617 13,024 13,764 16,368 18,352 19,536 25,234 27,528 32,736 36,704 37,851 39,072 50,468 55,056 75,702 100,936 110,112 151,404 201,872 302,808 403,744 605,616 and 1,211,232, with no remainder.
Since 1,211,232 cannot be divided by just 1 and 1,211,232, it is not a prime number.