"sixteenth" is an ordinal number. There is no ordinal number for an ordinal number!
Sixteenth or 16th
16th = sixteenth.
15th or fifteenth
sixteenth.
116 is already a cardinal number - perhaps you are looking for the ordinal number, which is one hundred and sixteenth.
The cardinal number sixteen (16) has the ordinal number sixteenth (16th). Both may be used as adjectives.
16th
51stFifty-first
The ordinal number premier in French corresponds to the English ordinal number "first".
An ordinal number shows a relative position, e.g., first, second, third, fourth, etc. In a sentence, ordinal numbers are used in the pattern The + Ordinal + Noun. For example, the first book of the series is about verbs.
Ninety-first or 91st