Somewhat; you can set a maximum value.
Why only somewhat? Limiting the maximum value and limiting the number of digits is not always the same thing. For example, 00001 and 10000 both have 5 digits. However, the number field will treat 00001 as being equal to just 1.
So, while you can set 99999 to prevent any number greater than or equal to 100,000, it will not require someone to enter at least 5 digits, unless you also set the minimum to 10000.
To set a maximum or minimum value, or both, go to the field's configuration settings by clicking the cogwheel icon to the right of the field, and scroll down to set a maximum or minimum value.