Sorry, this is not practical. Autocorrect would treat the following as individual cases:
7
17
27
117
Each would require its own AutoCorrect entry.
In addition, the space is a trigger character and you can't include it at the end of the entry.
If, instead, you just had the numbers, you would end up adding the nonbreaking space before a period or comma as well, since those are also triggers.

Are you aware that Ctrl+Shift+Space = nonbreaking space?

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