1997
1997 is the year Hong Kong was transferred from British to Chinese sovereignty.
- Odd
- Prime
Where 1997 fits
Why 1997 is special
The handover on 1 July ended 156 years of British rule under a treaty framework promising a distinct system for fifty years. 1997 is also the year a chess computer first beat a reigning world champion in a match, which is referenced almost as often.
Same number, different meanings
How 1997 is understood across different contexts — never implying one meaning because of another.
- Mathematics
The handover on 1 July ended 156 years of British rule under a treaty framework promising a distinct system for fifty years. 1997 is also the year a chess computer first beat a reigning world champion in a match, which is referenced almost as often.
- History
In 1997, a computer defeated the reigning world chess champion in a match for the first time.
- Science
In 1997, Dolly the sheep was announced, the first mammal cloned from an adult somatic cell (Scotland).
1997 is part of
Factors & digit properties
- Divisors (2)
- 1, 1997
- Prime factorisation
- 1997
- Digit sum
- 26
- Digital root
- 8
Representations
- Decimal
- 1997
- Scientific notation
- 1.997 × 10^3
Roman numerals
M C M X C V I I
MCMXCVII uses the subtractive pair XC: ten before a hundred — a hundred minus ten.
Binary
1 1 1 1 1 0 0 1 1 0 1
1 × 1,024 + 1 × 512 + 1 × 256 + 1 × 128 + 1 × 64 + 0 × 32 + 0 × 16 + 1 × 8 + 1 × 4 + 0 × 2 + 1 × 1 = 1,997
Octal
3 7 1 5
3 × 512 + 7 × 64 + 1 × 8 + 5 × 1 = 1,997
Hexadecimal
7 c d
7 × 256 + c × 16 + d × 1 = 1,997
Read as powers of two: 1,024 + 512 + 256 + 128 + 64 + 8 + 4 + 1 = 1,997.
In historical numeral systems
Egyptian
1 lotus, 9 coils of rope, 9 hobbles, 7 strokes
1 × 1,000 + 9 × 100 + 9 × 10 + 7 × 1 = 1,997. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
3 corner wedges + 3 vertical wedges (sixties place), 1 corner wedge + 7 vertical wedges (units place)
33 × 60 + 17 = 1997. Places are separated by a space on the tablet, with the higher place written first.
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
- Twin prime
Related numbers & connections
Deep Blue beat the world chess champion in 1997 and AlphaGo beat a top Go professional in 2016. The nineteen-year gap is a direct consequence of the difference in board size.
View 2016 →The Paris Agreement of 2015 lets each state set its own targets and achieved universal participation; earlier binding approaches did not. Enforceability and participation traded against each other.
View 2015 →Numbers Around Us
- appears alongside2016
why?
Strength 0.50, confidence "high".
- appears inHistorical years
why?
Strength 0.50, confidence "high".
History
In 1997, a computer defeated the reigning world chess champion in a match for the first time.
DocumentedHistoryGeography: globalPeriod: 1997Hong Kong transferred from British to Chinese sovereignty on 1 July 1997, ending 156 years of British rule under a framework promising a distinct system for fifty years. 1997 is also when a chess computer first beat a reigning world champion in a match.
DocumentedHistoryGeography: Hong KongPeriod: 1 July 1997
Science
In 1997, Dolly the sheep was announced, the first mammal cloned from an adult somatic cell (Scotland).
DocumentedScienceGeography: ScotlandPeriod: 1997
Common questions
Is 1997 a prime number?
Yes, 1997 is prime — it has exactly two positive divisors: 1 and itself.
What are the factors of 1997?
The factors of 1997 are 1, 1997.
What is 1997 in Roman numerals?
1997 in Roman numerals is MCMXCVII. XC is subtractive: ten before a hundred — a hundred minus ten. Written additively it would be MDCCCCLXXXXVII, 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