A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1750140 can be evenly divided by 1 2 3 4 5 6 7 9 10 12 14 15 18 20 21 27 28 30 35 36 42 45 54 60 63 70 84 90 105 108 126 135 140 180 189 210 252 270 315 378 420 463 540 630 756 926 945 1,260 1,389 1,852 1,890 2,315 2,778 3,241 3,780 4,167 4,630 5,556 6,482 6,945 8,334 9,260 9,723 12,501 12,964 13,890 16,205 16,668 19,446 20,835 25,002 27,780 29,169 32,410 38,892 41,670 48,615 50,004 58,338 62,505 64,820 83,340 87,507 97,230 116,676 125,010 145,845 175,014 194,460 250,020 291,690 350,028 437,535 583,380 875,070 and 1,750,140, with no remainder.
Since 1,750,140 cannot be divided by just 1 and 1,750,140, it is not a prime number.