A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 955152 can be evenly divided by 1 2 3 4 6 8 9 11 12 16 18 22 24 27 33 36 44 48 54 66 67 72 81 88 99 108 132 134 144 162 176 198 201 216 264 268 297 324 396 402 432 528 536 594 603 648 737 792 804 891 1,072 1,188 1,206 1,296 1,474 1,584 1,608 1,782 1,809 2,211 2,376 2,412 2,948 3,216 3,564 3,618 4,422 4,752 4,824 5,427 5,896 6,633 7,128 7,236 8,844 9,648 10,854 11,792 13,266 14,256 14,472 17,688 19,899 21,708 26,532 28,944 35,376 39,798 43,416 53,064 59,697 79,596 86,832 106,128 119,394 159,192 238,788 318,384 477,576 and 955,152, with no remainder.
Since 955,152 cannot be divided by just 1 and 955,152, it is not a prime number.