51 in words
51
fifty-one
51 is written fifty-one.
Ways to write it
- As an ordinal
- fifty-first
- Roman numeral
- LI
- Expanded form
- 50 + 1
Place value
| Place | Digit | Value |
|---|---|---|
| tens | 5 | 50 |
| ones | 1 | 1 |
Number facts
Quick check
What number comes just after 51?
Show the answer
52
Is 51 even or odd?
Show the answer
Odd
What is 51 + 10?
Show the answer
61
Practice with a game
Place Value Quest
Ones, tens, hundreds and thousands.
Times Tables Challenge
Practice any times table from 2× to 12×.Frequently asked questions
How do you write 51 in words?
51 is written "fifty-one".
Is 51 a prime number?
No. 51 is a composite number, because it has more than two factors.
What are the factors of 51?
The factors of 51 are 1, 3, 17 and 51.
How do you write 51 in Roman numerals?
51 in Roman numerals is LI.