Convert numbers to Chinese capital letters

The process of converting numbers into their corresponding Chinese characters is called "数字转中文大写" or "numerical conversion to Chinese uppercase." It involves assigning the appropriate Chinese character to each digit in a given number based on its position and value, following a set of rules and conventions. The resulting output is a string of Chinese characters that represents the given number in written form. This process is commonly used in (but not limited to) financial, legal, and administrative contexts involving Chinese characters.