How to deal with mixed type features?
The best will be to have domain knowledge and understand how this feature affects the target and what will be the best way to encode it:
First way: treat them all as a categorical feature with high cardinality.
Second way: split them into two columns, one categorical and one numerical. And then treat them separately.
Without domain knowledge in this case I cant think of on something better. Answering this question would help: Is the number really a number? Why can I have numbers and strings in the same column? How will this information might help my model?