421 in Words

How do you write 421 in words?

The number 421 is written four hundred twenty one in words. As an ordinal it is four hundred twenty first, and on a check you would write Four hundred twenty one and 00/100.

Last updated 19 June 2026

Other ways to write it

Cardinalfour hundred twenty one
Ordinalfour hundred twenty first
Currencyfour hundred twenty one dollars
Check formatFour hundred twenty one and 00/100

How number-to-words spelling works

A cardinal number names a quantity (four hundred twenty one), while an ordinal names a position (four hundred twenty first). English hyphenates compound numbers from twenty-one to ninety-nine and groups digits into thousands, millions, and billions.

For house-style rules on spelling out numbers, see the Chicago Manual of Style, or read our guide to spelling numbers in words.

Facts about 421

  • 421 is an odd number.
  • It is a prime number.
  • Digit sum: 7.
  • Roman numerals: CDXXI.
  • Binary: 110100101.
  • Hexadecimal: 1A5.
Place-value breakdown of 421
DigitPlace
4hundreds
2tens
1ones

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Frequently asked questions

How do you write 421 in words?

421 in words is "four hundred twenty one".

How do you spell 421?

421 is spelled "four hundred twenty one".

How do you write 421 on a check?

On a check, write "Four hundred twenty one and 00/100".

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