A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1444170 can be evenly divided by 1 2 3 5 6 7 10 13 14 15 21 23 26 30 35 39 42 46 65 69 70 78 91 105 115 130 138 161 182 195 210 230 273 299 322 345 390 455 483 529 546 598 690 805 897 910 966 1,058 1,365 1,495 1,587 1,610 1,794 2,093 2,415 2,645 2,730 2,990 3,174 3,703 4,186 4,485 4,830 5,290 6,279 6,877 7,406 7,935 8,970 10,465 11,109 12,558 13,754 15,870 18,515 20,631 20,930 22,218 31,395 34,385 37,030 41,262 48,139 55,545 62,790 68,770 96,278 103,155 111,090 144,417 206,310 240,695 288,834 481,390 722,085 and 1,444,170, with no remainder.
Since 1,444,170 cannot be divided by just 1 and 1,444,170, it is not a prime number.