917
The Porsche 917 is the car that won Le Mans and was then effectively banned.
- Odd
- Composite
Where 917 fits
Why 917 is special
Its 5-litre engine produced enough speed on the Mulsanne straight that organisers changed the rules and later added chicanes. Regulation followed capability rather than the other way round.
917 is part of
Factors & digit properties
- Divisors (4)
- 1, 7, 131, 917
- Prime factorisation
- 7 × 131
- Digit sum
- 17
- Digital root
- 8
Representations
- Decimal
- 917
- Scientific notation
- 9.170 × 10^2
Roman numerals
C M X V I I
CMXVII uses the subtractive pair CM: a hundred before a thousand — a thousand minus a hundred.
Binary
1 1 1 0 0 1 0 1 0 1
1 × 512 + 1 × 256 + 1 × 128 + 0 × 64 + 0 × 32 + 1 × 16 + 0 × 8 + 1 × 4 + 0 × 2 + 1 × 1 = 917
Octal
1 6 2 5
1 × 512 + 6 × 64 + 2 × 8 + 5 × 1 = 917
Hexadecimal
3 9 5
3 × 256 + 9 × 16 + 5 × 1 = 917
Read as powers of two: 512 + 256 + 128 + 16 + 4 + 1 = 917.
In historical numeral systems
Egyptian
9 coils of rope, 1 hobble, 7 strokes
9 × 100 + 1 × 10 + 7 × 1 = 917. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
1 corner wedge + 5 vertical wedges (sixties place), 1 corner wedge + 7 vertical wedges (units place)
15 × 60 + 17 = 917. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
sampi, then iota, then zeta, marked as a numeral
sampi-iota-zeta + keraia
sampi + iota + zeta written in descending order and added — the letters carry their values wherever they stand, so this is addition, not place value.
Hebrew numerals
tav, then tav, then qof, then yod, then zayin
tav-tav-qof-yod-zayin
tav (400) + tav (400) + qof (100) + yod (10) + zayin (7) = 917, written in descending order.
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
- Semiprime
Related numbers & connections
The Porsche 917 is a manufacturer model number, an identifier that became the name people use for the car.
The 917 was fast enough that Le Mans changed its rules, and the 959 was built for a rally category abolished before it could compete. Both were shaped by regulation more than by engineering.
View 959 →Numbers Around Us
- appears inNumbers assigned as identifiers
why?
Strength 0.50, confidence "high".
Other connections
- contrasts with959
why?
Strength 0.50, confidence "high".
Sport
The 917 reached speeds on the Le Mans straight that led directly to engine limits and, eventually, chicanes on the circuit. The car altered the track it raced on.
DocumentedSportGeography: Germany and FrancePeriod: 1969–1971
Common questions
Is 917 a prime number?
No, 917 is not prime.
What are the factors of 917?
The factors of 917 are 1, 7, 131, 917.
What is 917 in Roman numerals?
917 in Roman numerals is CMXVII. CM is subtractive: a hundred before a thousand — a thousand minus a hundred. Written additively it would be DCCCCXVII, 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: 1 reviewer-confirmed record, sourced and reviewed before publication.
Last reviewed: 15 July 2026