21 in Words – How to Spell 21
21 = Twenty-one
21 is written “twenty-one” in English.
Step by step
- Split 21 into groups of three digits: 21.
- Write each group as hundreds, tens and ones, hyphenating 21–99.
- Join the groups: Twenty-one.
As an ordinal (for dates, rankings and anniversaries), 21 becomes “twenty-first”, abbreviated 21st.
Details
- In words
- Twenty-one
- For a check
- Twenty-one and 00/100 dollars
- Uppercase
- TWENTY-ONE
- Digits
- 2
- Roman numerals
- XXI
How it works
English numbers are read in groups of three digits — ones, thousands, millions and so on. Each group is spoken as hundreds, tens and units, compound numbers from twenty-one to ninety-nine take a hyphen, and in American usage the word “and” is saved for the decimal point. On a check, the cents follow as a fraction over 100.
Nearby values
Related conversions
Frequently asked questions
How do you spell 21?
Twenty-one.
How do I write 21 dollars on a check?
Twenty-one and 00/100 dollars.
Is there a hyphen in 21?
Yes — compound numbers from twenty-one to ninety-nine are hyphenated.
What is 21 in Roman numerals?
XXI.