Why is Arduino Uno Rev3 input voltage specified up to 20V? OpAmp
The &quot;input&quot; in question is the power supply voltage. That Arduino uses an SPX1117 regulator.

Other considerations are thermal (on the high end) and the typical vs. worst-case dropout voltage of the regulator (on the low end).

Not important to this question, but for those using clones, note that the popular AMS1117 has a lower rated absolute maximum input voltage (15V).

As far as your op-amp circuit the Absolute Maximum input voltage to the divider would be 11.4V. The LMV358 is a bipolar technology part and does not have diodes from inputs to Vcc, so care is called for.  You can add a diode if you need to.