A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1234440 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 18 20 24 27 30 36 40 45 54 60 72 81 90 108 120 127 135 162 180 216 243 254 270 324 360 381 405 486 508 540 635 648 762 810 972 1,016 1,080 1,143 1,215 1,270 1,524 1,620 1,905 1,944 2,286 2,430 2,540 3,048 3,240 3,429 3,810 4,572 4,860 5,080 5,715 6,858 7,620 9,144 9,720 10,287 11,430 13,716 15,240 17,145 20,574 22,860 27,432 30,861 34,290 41,148 45,720 51,435 61,722 68,580 82,296 102,870 123,444 137,160 154,305 205,740 246,888 308,610 411,480 617,220 and 1,234,440, with no remainder.
Since 1,234,440 cannot be divided by just 1 and 1,234,440, it is not a prime number.