A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1990440 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 18 19 20 24 27 30 36 38 40 45 54 57 60 72 76 90 95 97 108 114 120 135 152 171 180 190 194 216 228 270 285 291 342 360 380 388 456 485 513 540 570 582 684 760 776 855 873 970 1,026 1,080 1,140 1,164 1,368 1,455 1,710 1,746 1,843 1,940 2,052 2,280 2,328 2,565 2,619 2,910 3,420 3,492 3,686 3,880 4,104 4,365 5,130 5,238 5,529 5,820 6,840 6,984 7,372 8,730 9,215 10,260 10,476 11,058 11,640 13,095 14,744 16,587 17,460 18,430 20,520 20,952 22,116 26,190 27,645 33,174 34,920 36,860 44,232 49,761 52,380 55,290 66,348 73,720 82,935 99,522 104,760 110,580 132,696 165,870 199,044 221,160 248,805 331,740 398,088 497,610 663,480 995,220 and 1,990,440, with no remainder.
Since 1,990,440 cannot be divided by just 1 and 1,990,440, it is not a prime number.