1951
1951 is the year the first commercially available computer was delivered.
- Odd
- Prime
Where 1951 fits
Why 1951 is special
The Ferranti Mark 1 in Britain and UNIVAC I in the United States both shipped in 1951. UNIVAC's televised prediction of the 1952 US election result, which the network initially refused to broadcast because it disagreed with the polls, put computing in front of the public.
1951 connects to:
- historical years — appears in
- 1946 — developed from
Same number, different meanings
How 1951 is understood across different contexts — never implying one meaning because of another.
- Mathematics
The Ferranti Mark 1 in Britain and UNIVAC I in the United States both shipped in 1951. UNIVAC's televised prediction of the 1952 US election result, which the network initially refused to broadcast because it disagreed with the polls, put computing in front of the public.
- History
In 1951, the first commercial computer sold in Britain, LEO, began running payroll and stock control for a catering company (England).
- Technology & computing
The Ferranti Mark 1 and UNIVAC I both shipped in 1951. UNIVAC's forecast of the 1952 US election was initially withheld by the broadcaster because it contradicted the polls; it was right, and that moment put computing in front of the public.
1951 is part of
Factors & digit properties
- Divisors (2)
- 1, 1951
- Prime factorisation
- 1951
- Digit sum
- 16
- Digital root
- 7
Representations
- Decimal
- 1951
- Scientific notation
- 1.951 × 10^3
Roman numerals
M C M L I
MCMLI uses the subtractive pair CM: a hundred before a thousand — a thousand minus a hundred.
Binary
1 1 1 1 0 0 1 1 1 1 1
1 × 1,024 + 1 × 512 + 1 × 256 + 1 × 128 + 0 × 64 + 0 × 32 + 1 × 16 + 1 × 8 + 1 × 4 + 1 × 2 + 1 × 1 = 1,951
Octal
3 6 3 7
3 × 512 + 6 × 64 + 3 × 8 + 7 × 1 = 1,951
Hexadecimal
7 9 f
7 × 256 + 9 × 16 + f × 1 = 1,951
Read as powers of two: 1,024 + 512 + 256 + 128 + 16 + 8 + 4 + 2 + 1 = 1,951.
In historical numeral systems
Egyptian
1 lotus, 9 coils of rope, 5 hobbles, 1 stroke
1 × 1,000 + 9 × 100 + 5 × 10 + 1 × 1 = 1,951. 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), 3 corner wedges + 1 vertical wedge (units place)
32 × 60 + 31 = 1951. 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
- Twin prime
Related numbers & connections
1951 is a year in the 20th century, in the 1950s.
Five years took computing from a rewired laboratory instrument to a product a customer could buy, and UNIVAC's televised election forecast put it in front of the public.
View 1946 →Numbers Around Us
- appears inHistorical years
why?
Strength 0.50, confidence "high".
Other connections
- developed from1946
why?
Strength 0.50, confidence "high".
History
In 1951, the first commercial computer sold in Britain, LEO, began running payroll and stock control for a catering company (England).
DocumentedHistoryGeography: EnglandPeriod: 1951
Technology & computing
The Ferranti Mark 1 and UNIVAC I both shipped in 1951. UNIVAC's forecast of the 1952 US election was initially withheld by the broadcaster because it contradicted the polls; it was right, and that moment put computing in front of the public.
DocumentedTechnology & computingPeriod: 1951
Common questions
Is 1951 a prime number?
Yes, 1951 is prime — it has exactly two positive divisors: 1 and itself.
What are the factors of 1951?
The factors of 1951 are 1, 1951.
What is 1951 in Roman numerals?
1951 in Roman numerals is MCMLI. CM is subtractive: a hundred before a thousand — a thousand minus a hundred. Written additively it would be MDCCCCLI, 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