521 in Words

How do you write 521 in words?

The number 521 is written five hundred twenty one in words. As an ordinal it is five hundred twenty first, and on a check you would write Five hundred twenty one and 00/100.

Last updated 19 June 2026

Other ways to write it

Cardinalfive hundred twenty one
Ordinalfive hundred twenty first
Currencyfive hundred twenty one dollars
Check formatFive hundred twenty one and 00/100

How number-to-words spelling works

A cardinal number names a quantity (five hundred twenty one), while an ordinal names a position (five 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 521

  • 521 is an odd number.
  • It is a prime number.
  • Digit sum: 8.
  • Roman numerals: DXXI.
  • Binary: 1000001001.
  • Hexadecimal: 209.
Place-value breakdown of 521
DigitPlace
5hundreds
2tens
1ones

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Frequently asked questions

How do you write 521 in words?

521 in words is "five hundred twenty one".

How do you spell 521?

521 is spelled "five hundred twenty one".

How do you write 521 on a check?

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

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