Since when does 500 lumens = 60W bulb?
Perhaps a dimwit wrote the description, or maybe the writer thought dimwit customers would not see the discrepancy. Some reviewers of these dimmable bulbs on Amazon were quite disappointed with them because they became so dim that they did not shine at all. Others said the lights were much brighter than the 40 watt bulbs they replaced with these 500 lumens bulbs.
The flux capacitor needed calibration.
A "dirty secret" of dimmable LEDs is that they're only guaranteed dimmable with a dimmer that is specifically intended to pair with the particular LED bulbs......
Several issues: an pre-existing dimmer used with incandescent fixtures dims the lights via a different parameter than needed by an LED for dimming. The typical result of this pair is LED lamps that dim only in large steps, and don't work at all with lower dimmer settings.
On top of that issue, there are both forward-biased, and reverse-biased LED lights Pairing an LED dimmer intended for forward biasing with a lamp that is reverse-biased will also not work well. And it's nearly impossible to get information from manufacturers about which bias is used by a particular lamp or dimmer.
(I'm not an expert with this-- but our company has pretty extensive experience with commercial lighting for restaurants, churches, etc, so the lighting guys here have spent quite a bit of time helping customers figure out why their 'dimmable' LEDs are not dimming as expected......)