For me numbers are stored in one language or the other, but are always recalled in the same language. For example, my SSN is in English but my garage door opener code is Chinese.

For some reason, I remember numbers like that as though I were typing them on a numpad. I automatically visualize a numpad and remember the sequence of numbers as distinct locations on it. Funnily enough, even phone numbers use this computer numpad rather than the number pad on a phone.

You can't visualize the numbers? Or translate the "audio" in your mind?

I can, but it's easier to write it, if I'm at a desk. Audio-translating is harder than it seems that it should be... especially if I"m struggling to recall the number. I suspect that recall and translation are like lead guitar and vocals.