1817
1817 is the year the stethoscope was invented.
- Odd
- Composite
Where 1817 fits
Why 1817 is special
Laennec rolled paper into a tube because he was uncomfortable placing his ear directly on a female patient's chest. Modesty produced the defining instrument of clinical medicine.
Same number, different meanings
How 1817 is understood across different contexts — never implying one meaning because of another.
- Mathematics
Laennec rolled paper into a tube because he was uncomfortable placing his ear directly on a female patient's chest. Modesty produced the defining instrument of clinical medicine.
- History
In 1817, David Ricardo set out comparative advantage, the argument that trade can benefit both sides even when one is better at everything (England).
- Science
Laennec devised the stethoscope in 1817 to avoid direct ear-to-chest contact with a female patient. The instrument turned out to hear better than the ear alone, which was not the reason for making it.
1817 is part of
Factors & digit properties
- Divisors (4)
- 1, 23, 79, 1817
- Prime factorisation
- 23 × 79
- Digit sum
- 17
- Digital root
- 8
Representations
- Decimal
- 1817
- Scientific notation
- 1.817 × 10^3
Roman numerals
M D C C C X V I I
Binary
1 1 1 0 0 0 1 1 0 0 1
1 × 1,024 + 1 × 512 + 1 × 256 + 0 × 128 + 0 × 64 + 0 × 32 + 1 × 16 + 1 × 8 + 0 × 4 + 0 × 2 + 1 × 1 = 1,817
Octal
3 4 3 1
3 × 512 + 4 × 64 + 3 × 8 + 1 × 1 = 1,817
Hexadecimal
7 1 9
7 × 256 + 1 × 16 + 9 × 1 = 1,817
Read as powers of two: 1,024 + 512 + 256 + 16 + 8 + 1 = 1,817.
In historical numeral systems
Egyptian
1 lotus, 8 coils of rope, 1 hobble, 7 strokes
1 × 1,000 + 8 × 100 + 1 × 10 + 7 × 1 = 1,817. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
3 corner wedges (sixties place), 1 corner wedge + 7 vertical wedges (units place)
30 × 60 + 17 = 1817. 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
- Semiprime
Related numbers & connections
1817 is a year in the 19th century, in the 1810s.
The stethoscope of 1817 let physicians hear inside the body, and Koch's identification of the tuberculosis bacterium in 1882 explained much of what they had been listening to.
View 1882 →Numbers Around Us
- appears inHistorical years
why?
Strength 0.50, confidence "high".
Other connections
- developed from1882
why?
Strength 0.50, confidence "high".
History
In 1817, David Ricardo set out comparative advantage, the argument that trade can benefit both sides even when one is better at everything (England).
DocumentedHistoryGeography: EnglandPeriod: 1817
Science
Laennec devised the stethoscope in 1817 to avoid direct ear-to-chest contact with a female patient. The instrument turned out to hear better than the ear alone, which was not the reason for making it.
DocumentedScienceGeography: FrancePeriod: 1817
Common questions
Is 1817 a prime number?
No, 1817 is not prime.
What are the factors of 1817?
The factors of 1817 are 1, 23, 79, 1817.
What is 1817 in Roman numerals?
1817 in Roman numerals is MDCCCXVII.
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