I guess that the "Combining Cyrillic Ten Millions Sign" could do the job: ꙰ ꙰

Though you point it seems is more like using only a small set of symbols. Obviously, to render large number you need to introduce new syntax apparatus if keeping terseness is a desired constraint.

Just like you would wrote 1×10⁷ or 1e7, you can have say a single point on one line, and an heptagon or seven points on an other, still juxtaposing these two columned digits. In Unicode, it seems these last symbols are not present, but instead you can use cards from different games.

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How fun! :D