1920
1920 is the year the League of Nations began work.
- Even
- Composite
Where 1920 fits
Why 1920 is special
The United States never joined, despite an American president having proposed it. The League had no armed force and depended on member states acting, which is the structural weakness its successor tried to address.
1920 connects to:
- historical years — appears in
- 1945 — contrasts with
Same number, different meanings
How 1920 is understood across different contexts — never implying one meaning because of another.
- Mathematics
The United States never joined, despite an American president having proposed it. The League had no armed force and depended on member states acting, which is the structural weakness its successor tried to address.
- History
In 1920, the League of Nations was established.
- Technology & computing
In 1920, KDKA in Pittsburgh began regularly scheduled radio broadcasting, generally taken as the start of commercial broadcasting (United States).
- Law & regulation
Woodrow Wilson proposed the League and the US Senate declined to ratify membership. An organisation designed around collective enforcement, without its principal advocate and with no forces of its own, had limited means of doing what it existed for.
1920 is part of
Factors & digit properties
- Divisors (32)
- 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 48, 60, 64, 80, 96, 120, 128, 160, 192, 240, 320, 384, 480, 640, 960, 1920
- Prime factorisation
- 2^7 × 3 × 5
- Digit sum
- 12
- Digital root
- 3
Representations
- Decimal
- 1920
- Scientific notation
- 1.920 × 10^3
Roman numerals
M C M X X
MCMXX uses the subtractive pair CM: a hundred before a thousand — a thousand minus a hundred.
Binary
1 1 1 1 0 0 0 0 0 0 0
1 × 1,024 + 1 × 512 + 1 × 256 + 1 × 128 + 0 × 64 + 0 × 32 + 0 × 16 + 0 × 8 + 0 × 4 + 0 × 2 + 0 × 1 = 1,920
Octal
3 6 0 0
3 × 512 + 6 × 64 + 0 × 8 + 0 × 1 = 1,920
Hexadecimal
7 8 0
7 × 256 + 8 × 16 + 0 × 1 = 1,920
Read as powers of two: 1,024 + 512 + 256 + 128 = 1,920.
In historical numeral systems
Egyptian
1 lotus, 9 coils of rope, 2 hobbles
1 × 1,000 + 9 × 100 + 2 × 10 = 1,920. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
3 corner wedges + 2 vertical wedges (sixties place), empty units place
32 × 60 + 0 = 1920. Places are separated by a space on the tablet, with the higher place written first. The second place is empty, and this is precisely the case the early system could not write unambiguously — the same wedges alone would also read as 1.
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
- Harshad (Niven) number
Related numbers & connections
1920 is a year in the 20th century, in the 1920s.
The League of Nations began work in 1920 without the country that proposed it; the United Nations from 1945 was designed around that failure.
View 1945 →Numbers Around Us
- appears inHistorical years
why?
Strength 0.50, confidence "high".
Other connections
- contrasts with1945
why?
Strength 0.50, confidence "high".
History
In 1920, the League of Nations was established.
DocumentedHistoryGeography: globalPeriod: 1920
Technology & computing
In 1920, KDKA in Pittsburgh began regularly scheduled radio broadcasting, generally taken as the start of commercial broadcasting (United States).
DocumentedTechnology & computingGeography: United StatesPeriod: 1920
Law & regulation
Woodrow Wilson proposed the League and the US Senate declined to ratify membership. An organisation designed around collective enforcement, without its principal advocate and with no forces of its own, had limited means of doing what it existed for.
DocumentedLaw & regulationGeography: International — member statesPeriod: 1920
Common questions
Is 1920 a prime number?
No, 1920 is not prime.
What are the factors of 1920?
The factors of 1920 are 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 48, 60, 64, 80, 96, 120, 128, 160, 192, 240, 320, 384, 480, 640, 960, 1920.
What is 1920 in Roman numerals?
1920 in Roman numerals is MCMXX. CM is subtractive: a hundred before a thousand — a thousand minus a hundred. Written additively it would be MDCCCCXX, 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