> I associate numbers with taste (2 and 5 are sweeter, 3 is salty, 7 is bitter and so on)
That sounds like textbook "synesthesia" to me? I don’t associate numbers with any taste, smell, or color, and would wager that this is more common than the opposite.
And interestingly, in comparison, the mappings in synesthesia are much more arbitrary: while there are certain associations that are more common (numbers and colors, for example), there's not broad agreement on what color each number is.
That sounds like textbook "synesthesia" to me? I don’t associate numbers with any taste, smell, or color, and would wager that this is more common than the opposite.