One option is a numeric text input that also lists some non-numeric options (usually shown in a pulldown menu by the browser):
<input type="text" list="list" inputmode="numeric"/>
<datalist id="list">
<option value="ABC"/>
<option value="DEF"/>
<option value="GHI"/>
</datalist>
However, if the overall set of options, including numbers, is limited, then a <select>
might be more appropriate, and is more widely supported:
<select>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="ABC">ABC</option>
<option value="DEF">DEF</option>
<option value="GHI">GHI</option>
</select>
See this fiddle.