1940
1940 is the year of the Battle of Britain.
- Even
- Composite
Where 1940 fits
Why 1940 is special
It was the first major campaign fought entirely by air forces. Radar and a centralised control system mattered more than aircraft quality: Britain could direct fighters to where bombers actually were rather than patrolling and hoping.
1940 connects to:
- historical years — appears in
- 1935 — is associated with
Same number, different meanings
How 1940 is understood across different contexts — never implying one meaning because of another.
- Mathematics
It was the first major campaign fought entirely by air forces. Radar and a centralised control system mattered more than aircraft quality: Britain could direct fighters to where bombers actually were rather than patrolling and hoping.
- History
In 1940, the Battle of Britain was fought in the skies over southern England (Britain).
- Technology & computing
In 1940, The cavity magnetron made centimetric radar small enough to fit in an aircraft, and was handed to the United States as part of the Tizard Mission (United Kingdom).
1940 is part of
Factors & digit properties
- Divisors (12)
- 1, 2, 4, 5, 10, 20, 97, 194, 388, 485, 970, 1940
- Prime factorisation
- 2^2 × 5 × 97
- Digit sum
- 14
- Digital root
- 5
Representations
- Decimal
- 1940
- Scientific notation
- 1.940 × 10^3
Roman numerals
M C M X L
MCMXL uses the subtractive pair XL: ten before fifty — fifty minus ten.
Binary
1 1 1 1 0 0 1 0 1 0 0
1 × 1,024 + 1 × 512 + 1 × 256 + 1 × 128 + 0 × 64 + 0 × 32 + 1 × 16 + 0 × 8 + 1 × 4 + 0 × 2 + 0 × 1 = 1,940
Octal
3 6 2 4
3 × 512 + 6 × 64 + 2 × 8 + 4 × 1 = 1,940
Hexadecimal
7 9 4
7 × 256 + 9 × 16 + 4 × 1 = 1,940
Read as powers of two: 1,024 + 512 + 256 + 128 + 16 + 4 = 1,940.
In historical numeral systems
Egyptian
1 lotus, 9 coils of rope, 4 hobbles
1 × 1,000 + 9 × 100 + 4 × 10 = 1,940. 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), 2 corner wedges (units place)
32 × 60 + 20 = 1940. 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
Related numbers & connections
1940 is a year in the 20th century, in the 1940s.
Radar was demonstrated in Britain in 1935 and was decisive in the Battle of Britain five years later, because it let fighters be sent where bombers actually were.
View 1935 →Numbers Around Us
- appears inHistorical years
why?
Strength 0.50, confidence "high".
Other connections
- is associated with1935
why?
Strength 0.50, confidence "high".
History
In 1940, the Battle of Britain was fought in the skies over southern England (Britain).
DocumentedHistoryGeography: BritainPeriod: 1940The Battle of Britain was the first campaign fought entirely between air forces. Radar feeding a centralised control room was decisive: fighters could be sent where bombers actually were rather than flying patrols and hoping to meet them.
DocumentedHistoryGeography: United KingdomPeriod: 1940
Technology & computing
In 1940, The cavity magnetron made centimetric radar small enough to fit in an aircraft, and was handed to the United States as part of the Tizard Mission (United Kingdom).
DocumentedTechnology & computingGeography: United KingdomPeriod: 1940
Common questions
Is 1940 a prime number?
No, 1940 is not prime.
What are the factors of 1940?
The factors of 1940 are 1, 2, 4, 5, 10, 20, 97, 194, 388, 485, 970, 1940.
What is 1940 in Roman numerals?
1940 in Roman numerals is MCMXL. XL is subtractive: ten before fifty — fifty minus ten. Written additively it would be MDCCCCXXXX, 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