I may be remembering it wrong but, less than 2 years ago, there was some issue about Android not firing change events on those for some reason and it was in a version of the browser that a lot of users were going to be using for a long time to come because they're weren't getting OTA updates anymore. It may not be a real concern anymore but it's junk like that just makes these things a pain. Unfortunatley, there's no other good way to get the number pad, which I don't think is a real issue unless individual users will be filling out your forms a lot, like for a data entry application, in which case a custom number pad might be worth considering.