As pointed out, if power factor is the subject, then it must be relating to the AC input, not the LEDs themselves. There must always be a power supply and that power supply will be some form of rectifier and transformer combination. That will always therefore have a power factor of less than 1.0, but how much depends entirely on the design and varies quite a bit. On top of that, there will be both displacement PF and distortion PF because it will always be a non-linear load on the AC side. Some more responsible mfrs opt for providing PFC (power factor correction) in their design to minimize the impact on the supply side, but the cheaper the supplier, the less likely that will be the case. Efforts to mandate PFC in power supply designs have been thwarted by the flood of cheap products sold via on-line retailers from areas of the world without these regulations to the general populace that has no clue about such matters. Bottom line, if it's a concern, investigate it and if a supplier claims ignorance, assume it's a scam. They ALL know about it.
