1971
1971 is the year the first microprocessor and the first email were released.
- Odd
- Composite
Where 1971 fits
Why 1971 is special
Intel's 4004 shipped and Ray Tomlinson sent the first network email, choosing the @ sign because it was the only preposition on the keyboard. Britain also decimalised its currency that February.
1971 is part of
Factors & digit properties
- Divisors (8)
- 1, 3, 9, 27, 73, 219, 657, 1971
- Prime factorisation
- 3^3 × 73
- Digit sum
- 18
- Digital root
- 9
Representations
- Decimal
- 1971
- Scientific notation
- 1.971 × 10^3
Roman numerals
M C M L X X I
MCMLXXI uses the subtractive pair CM: a hundred before a thousand — a thousand minus a hundred.
Binary
1 1 1 1 0 1 1 0 0 1 1
1 × 1,024 + 1 × 512 + 1 × 256 + 1 × 128 + 0 × 64 + 1 × 32 + 1 × 16 + 0 × 8 + 0 × 4 + 1 × 2 + 1 × 1 = 1,971
Octal
3 6 6 3
3 × 512 + 6 × 64 + 6 × 8 + 3 × 1 = 1,971
Hexadecimal
7 b 3
7 × 256 + b × 16 + 3 × 1 = 1,971
Read as powers of two: 1,024 + 512 + 256 + 128 + 32 + 16 + 2 + 1 = 1,971.
In historical numeral systems
Egyptian
1 lotus, 9 coils of rope, 7 hobbles, 1 stroke
1 × 1,000 + 9 × 100 + 7 × 10 + 1 × 1 = 1,971. 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), 5 corner wedges + 1 vertical wedge (units place)
32 × 60 + 51 = 1971. 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
Related numbers & connections
1971 is a year in the 20th century, in the 1970s.
The term is traced to a group of California students meeting at 4:20 in about 1971.
View 420 →Technology & computing
In 1971, the first commercial microprocessor, the Intel 4004, was released (North America).
DocumentedTechnology & computingGeography: North AmericaPeriod: 1971Ray Tomlinson picked @ for network email because it was the only preposition on the keyboard and appeared in no one's name. Intel's 4004 shipped the same year, and Britain decimalised its currency that February.
DocumentedTechnology & computingPeriod: 1971
Common questions
Is 1971 a prime number?
No, 1971 is not prime.
What are the factors of 1971?
The factors of 1971 are 1, 3, 9, 27, 73, 219, 657, 1971.
What is 1971 in Roman numerals?
1971 in Roman numerals is MCMLXXI. CM is subtractive: a hundred before a thousand — a thousand minus a hundred. Written additively it would be MDCCCCLXXI, 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