Number Words Writer

This app lets you convert numbers to their word form up to 69 digits, and it can include decimals. It lets you change the decimal format and share or copy the output. You can record numbers to history. History can be exported/imported to a .csv file (Android 4.4+.) The settings include dark or light themes, thousands separators, and capitalizing words. The app could be useful when writing numbers on bank checks.

Try the Lite Version:
https://play.google.com/store/apps/details?id=com.grantojanen.numberwordswriterfree