1902
1902 is the year air conditioning was invented.
- Even
- Composite
Where 1902 fits
Why 1902 is special
It was built to control humidity in a printing plant, not to cool people — paper expanded and contracted enough to ruin colour registration. Comfort cooling was a later application of a manufacturing fix.
1902 is part of
Factors & digit properties
- Divisors (8)
- 1, 2, 3, 6, 317, 634, 951, 1902
- Prime factorisation
- 2 × 3 × 317
- Digit sum
- 12
- Digital root
- 3
Representations
- Decimal
- 1902
- Scientific notation
- 1.902 × 10^3
Roman numerals
M C M I I
MCMII uses the subtractive pair CM: a hundred before a thousand — a thousand minus a hundred.
Binary
1 1 1 0 1 1 0 1 1 1 0
1 × 1,024 + 1 × 512 + 1 × 256 + 0 × 128 + 1 × 64 + 1 × 32 + 0 × 16 + 1 × 8 + 1 × 4 + 1 × 2 + 0 × 1 = 1,902
Octal
3 5 5 6
3 × 512 + 5 × 64 + 5 × 8 + 6 × 1 = 1,902
Hexadecimal
7 6 e
7 × 256 + 6 × 16 + e × 1 = 1,902
Read as powers of two: 1,024 + 512 + 256 + 64 + 32 + 8 + 4 + 2 = 1,902.
In historical numeral systems
Egyptian
1 lotus, 9 coils of rope, 2 strokes
1 × 1,000 + 9 × 100 + 2 × 1 = 1,902. 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), 4 corner wedges + 2 vertical wedges (units place)
31 × 60 + 42 = 1902. 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
- Abundant number
- Happy number
Related numbers & connections
1902 is a year in the 20th century, in the 1900s.
Air conditioning in 1902 was built to control humidity for printing, and the moving assembly line of 1913 industrialised production. Both were manufacturing fixes whose social effects came later.
View 1913 →Numbers Around Us
- appears inHistorical years
why?
Strength 0.50, confidence "high".
Other connections
- developed from1913
why?
Strength 0.50, confidence "high".
Technology & computing
In 1902, Willis Carrier designed the first modern air conditioning system, initially to control humidity in a printing plant (United States).
DocumentedTechnology & computingGeography: United StatesPeriod: 1902Willis Carrier's 1902 system controlled humidity so that printing paper held its dimensions between colour passes. Cooling people was a side effect that took decades to become the primary purpose, and it reshaped where in the world it is practical to live and work.
DocumentedTechnology & computingPeriod: 1902
Common questions
Is 1902 a prime number?
No, 1902 is not prime.
What are the factors of 1902?
The factors of 1902 are 1, 2, 3, 6, 317, 634, 951, 1902.
What is 1902 in Roman numerals?
1902 in Roman numerals is MCMII. CM is subtractive: a hundred before a thousand — a thousand minus a hundred. Written additively it would be MDCCCCII, 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