297
A4 paper is 297 mm tall.
- Odd
- Composite
Where 297 fits
Why 297 is special
297 divided by 210 is very close to the square root of two, which is what lets a sheet be halved indefinitely without changing its proportions. North America uses Letter size instead, which has no such property and is why international document templates so often break.
Same number, different meanings
How 297 is understood across different contexts — never implying one meaning because of another.
- Mathematics
297 divided by 210 is very close to the square root of two, which is what lets a sheet be halved indefinitely without changing its proportions. North America uses Letter size instead, which has no such property and is why international document templates so often break.
- Technology & computing
There are 297 millimetres along the long edge of a sheet of A4 paper (worldwide, ISO 216). The 297-by-210 ratio is the square root of two, so folding a sheet in half gives the same proportions again — which is the whole design of the series, and why enlarging A4 to A3 is exactly 141 per cent.
- Everyday life
297 divided by 210 is very nearly the square root of two, the only ratio that stays the same when a sheet is halved. North American Letter size has no such property, which is the practical reason international document templates so often break.
- Geography
+297 reaches Aruba, part of the Kingdom of the Netherlands but outside the EU, with its own parliament and the Aruban florin.
Factors & digit properties
- Divisors (8)
- 1, 3, 9, 11, 27, 33, 99, 297
- Prime factorisation
- 3^3 × 11
- Digit sum
- 18
- Digital root
- 9
Representations
- Decimal
- 297
- Scientific notation
- 2.970 × 10^2
Roman numerals
C C X C V I I
CCXCVII uses the subtractive pair XC: ten before a hundred — a hundred minus ten.
Binary
1 0 0 1 0 1 0 0 1
1 × 256 + 0 × 128 + 0 × 64 + 1 × 32 + 0 × 16 + 1 × 8 + 0 × 4 + 0 × 2 + 1 × 1 = 297
Octal
4 5 1
4 × 64 + 5 × 8 + 1 × 1 = 297
Hexadecimal
1 2 9
1 × 256 + 2 × 16 + 9 × 1 = 297
Read as powers of two: 256 + 32 + 8 + 1 = 297.
In historical numeral systems
Egyptian
2 coils of rope, 9 hobbles, 7 strokes
2 × 100 + 9 × 10 + 7 × 1 = 297. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
4 vertical wedges (sixties place), 5 corner wedges + 7 vertical wedges (units place)
4 × 60 + 57 = 297. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
sigma, then koppa, then zeta, marked as a numeral
sigma-koppa-zeta + keraia
sigma + koppa + zeta written in descending order and added — the letters carry their values wherever they stand, so this is addition, not place value.
Hebrew numerals
resh, then tsadi, then zayin
resh-tsadi-zayin
resh (200) + tsadi (90) + zayin (7) = 297, written in descending order.
Maya
2 bars + 4 dots (upper, twenties place) over 3 bars + 2 dots (lower, units place)
14 × 20 + 17 = 297. Places stack vertically with the smallest at the bottom, so the upper group is worth twenty times the lower.
Systems that simply cannot reach this value are left out. Where a script needs a font most readers do not have, the reading is given instead of the glyphs — see number systems for each system in full.
Other mathematical patterns
- Deficient number
- Kaprekar number
- Lucky number (mathematical sieve)
Related numbers & connections
A3 is 297 by 420 mm, an A4 sheet doubled along its short side. Each step up the series doubles the area and preserves the shape.
View 420 →Curaçao and Aruba are both constituent parts of the Kingdom of the Netherlands with their own governments, and both sit outside the European Union.
View 599 →Technology & computing
There are 297 millimetres along the long edge of a sheet of A4 paper (worldwide, ISO 216). The 297-by-210 ratio is the square root of two, so folding a sheet in half gives the same proportions again — which is the whole design of the series, and why enlarging A4 to A3 is exactly 141 per cent.
DocumentedTechnology & computingGeography: worldwide, ISO 216
Everyday life
297 divided by 210 is very nearly the square root of two, the only ratio that stays the same when a sheet is halved. North American Letter size has no such property, which is the practical reason international document templates so often break.
DocumentedEveryday life
Geography
+297 reaches Aruba, part of the Kingdom of the Netherlands but outside the EU, with its own parliament and the Aruban florin.
DocumentedGeographyGeography: Aruba
Common questions
Is 297 a prime number?
No, 297 is not prime.
What are the factors of 297?
The factors of 297 are 1, 3, 9, 11, 27, 33, 99, 297.
What is 297 in Roman numerals?
297 in Roman numerals is CCXCVII. XC is subtractive: ten before a hundred — a hundred minus ten. Written additively it would be CCLXXXXVII, which Roman inscriptions used freely — the strict subtractive form is a later convention.
About this page's data
Mathematical facts:computed directly from the number's value — nothing to source or verify externally.
Contextual records: 3 reviewer-confirmed records, sourced and reviewed before publication.
Last reviewed: 15 July 2026