Did you mean “aren’t”?
Back to OP:
Harvey Mudd’s SAT Math 25th percentile is 780.
Penn’s overall SAT 25th percentile is 1460
Cornell’s 50th percentile for Math and Total are 770 and 1480
Northwestern’s 25-75% is 1440-1550.
When you say “and some safeties”, do you consider these to be match/target schools? You are at or below the mid-point for all of these very competitive schools. If you don’t think your score represents your abilities, and think you can score substantially higher, I would suggest re-taking it.