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 24 August 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 421 is written

421 is the sum of its place values, 400 + 20 + 1, and is written four hundred twenty-one.

Its ordinal form is four hundred twenty-first — only the final element takes the ordinal ending — and on a check the amount line reads "Four hundred twenty-one and 00/100", where 00/100 stands for zero cents.

British English inserts "and" before the last part, giving four hundred and twenty-one, where American English writes four hundred twenty-one without it.

Its Roman numeral CDXXI uses subtractive notation: CD means 400, written as C before D instead of repeating C.

For house-style rules on spelling out numbers, see the Chicago Manual of Style.

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".