Sign inBook a free assessment

Country and language

Country and language: Hong Kong

Country and language

321 in words

321

three hundred and twenty-one

321 is written three hundred and twenty-one.

Ways to write it

As an ordinal
three hundred and twenty-first
Roman numeral
CCCXXI
Expanded form
300 + 20 + 1

Place value

PlaceDigitValue
hundreds3300
tens220
ones11

Number facts

Even or odd
Odd
Prime or composite
Composite
Factors
1, 3, 107 and 321 (4 factors)
First 10 multiples
321, 642, 963, 1,284, 1,605, 1,926, 2,247, 2,568, 2,889, 3,210
Square
321 × 321 = 103,041
Square root
≈ 17.92
Sum of the digits
3 + 2 + 1 = 6
Rounded to the nearest 10
320
Rounded to the nearest 100
300
Number before
320
Number after
322
In binary
101000001

Quick check

  1. What number comes just after 321?

    Show the answer

    322

  2. Is 321 even or odd?

    Show the answer

    Odd

  3. What is 321 + 10?

    Show the answer

    331

Practise with a game

Frequently asked questions

How do you write 321 in words?

321 is written "three hundred and twenty-one".

Is 321 a prime number?

No. 321 is a composite number, because it has more than two factors.

What are the factors of 321?

The factors of 321 are 1, 3, 107 and 321.

How do you write 321 in Roman numerals?

321 in Roman numerals is CCCXXI.