31 in words
British English
thirty-one
Quick reference
- In figures
- 31
- British English
- thirty-one
- American English
- The same (why they differ)
- Ordinal
- thirty-first (31st)
- Roman numeral
- XXXI
- Place value
- 3 in the tens column; 1 in the ones column
- Expanded form
- 30 + 1
- Standard form
- 3.1 × 10¹
- Even or odd
- Odd
- Prime factors
- None but itself and one: it is prime
Convert any other number, up to thirty-six digits.