1917
1917 is the year of the Russian Revolution.
- Odd
- Composite
Where 1917 fits
Why 1917 is special
There were two: a February revolution that removed the Tsar and installed a provisional government, and an October one that replaced it with Bolshevik rule. Both are dated by the old Russian calendar, which is why the October revolution is commemorated in November.
1917 is part of
Factors & digit properties
- Divisors (8)
- 1, 3, 9, 27, 71, 213, 639, 1917
- Prime factorisation
- 3^3 × 71
- Digit sum
- 18
- Digital root
- 9
Representations
- Decimal
- 1917
- Scientific notation
- 1.917 × 10^3
Roman numerals
M C M X V I I
MCMXVII uses the subtractive pair CM: a hundred before a thousand — a thousand minus a hundred.
Binary
1 1 1 0 1 1 1 1 1 0 1
1 × 1,024 + 1 × 512 + 1 × 256 + 0 × 128 + 1 × 64 + 1 × 32 + 1 × 16 + 1 × 8 + 1 × 4 + 0 × 2 + 1 × 1 = 1,917
Octal
3 5 7 5
3 × 512 + 5 × 64 + 7 × 8 + 5 × 1 = 1,917
Hexadecimal
7 7 d
7 × 256 + 7 × 16 + d × 1 = 1,917
Read as powers of two: 1,024 + 512 + 256 + 64 + 32 + 16 + 8 + 4 + 1 = 1,917.
In historical numeral systems
Egyptian
1 lotus, 9 coils of rope, 1 hobble, 7 strokes
1 × 1,000 + 9 × 100 + 1 × 10 + 7 × 1 = 1,917. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
3 corner wedges + 1 vertical wedge (sixties place), 5 corner wedges + 7 vertical wedges (units place)
31 × 60 + 57 = 1917. 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
Related numbers & connections
1917 is a year in the 20th century, in the 1910s.
The Romanov dynasty began in 1613 and ended with the revolution of 1917, having ruled Russia for 304 years.
View 1613 →History
February removed the Tsar and installed a provisional government; October replaced it with Bolshevik rule. Both are named for the old Russian calendar, which is why the October Revolution is commemorated in November.
DocumentedHistoryGeography: RussiaPeriod: 1917In 1917, the Russian Revolution brought the Bolsheviks to power (Russia).
DocumentedHistoryGeography: RussiaPeriod: 1917
Common questions
Is 1917 a prime number?
No, 1917 is not prime.
What are the factors of 1917?
The factors of 1917 are 1, 3, 9, 27, 71, 213, 639, 1917.
What is 1917 in Roman numerals?
1917 in Roman numerals is MCMXVII. CM is subtractive: a hundred before a thousand — a thousand minus a hundred. Written additively it would be MDCCCCXVII, 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: 2 reviewer-confirmed records, sourced and reviewed before publication.
Last reviewed: 15 July 2026