May 28, 2020
You are correct when you note that a "perfect" PSAT score is 2400, not 1600 (that's if you add a zero to your total to compare it to the SAT scoring system). The PSAT scoring system, as explained by the College Board, is below:
The PSAT/NMSQT score reports provide three different scores on the 20-to-80 scale. One each for verbal skills, math skills, and writing skills. The average verbal, math, and writing skills score for juniors is about 49.
Also on your score report is the Selection Index, which is the sum of the three scores (V + M + W). The Selection Index ranges from 60 to 240. The average Selection Index of juniors is about 147.
Those who have told you that your score was actually a 1490 out of 1600 are probably confused because the old PSAT was composed of only two scores--not three--since the writing component was recently added.
Thus, as you can see from the College Board information, your scores are slightly above the national average. That makes them "good" in many eyes but not so good if you are aiming for Ivy League universities or other highly competitive schools. However, there are many factors that go into admission decisions--not just test results--and these are only PSAT's, not the real deal.