Not the GP, but for me, in the context of numbers that I use on a keypad (or, ahem, in the context of a rotary dial), the physical actions are linked into the m

Not the GP, but for me, in the context of numbers that I use on a keypad (or, ahem, in the context of a rotary dial), the physical actions are linked into the memorization, along with some combination of aural and visual memory.