1990
1990 is the year Germany reunified and Nelson Mandela was released.
- Even
- Composite
Where 1990 fits
Why 1990 is special
Reunification took under a year from the Wall opening, faster than almost anyone had planned for. Mandela's release in February began a negotiation that produced South Africa's first democratic election four years later.
Same number, different meanings
How 1990 is understood across different contexts — never implying one meaning because of another.
- Mathematics
Reunification took under a year from the Wall opening, faster than almost anyone had planned for. Mandela's release in February began a negotiation that produced South Africa's first democratic election four years later.
- History
In 1990, the Hubble Space Telescope was launched, and Nelson Mandela was released from prison.
- Science
In 1990, The Hubble Space Telescope was launched, and its mirror was found to be misground before a servicing mission corrected it.
1990 is part of
Factors & digit properties
- Divisors (8)
- 1, 2, 5, 10, 199, 398, 995, 1990
- Prime factorisation
- 2 × 5 × 199
- Digit sum
- 19
- Digital root
- 1
Representations
- Decimal
- 1990
- Scientific notation
- 1.990 × 10^3
Roman numerals
M C M X C
MCMXC uses the subtractive pair XC: ten before a hundred — a hundred minus ten.
Binary
1 1 1 1 1 0 0 0 1 1 0
1 × 1,024 + 1 × 512 + 1 × 256 + 1 × 128 + 1 × 64 + 0 × 32 + 0 × 16 + 0 × 8 + 1 × 4 + 1 × 2 + 0 × 1 = 1,990
Octal
3 7 0 6
3 × 512 + 7 × 64 + 0 × 8 + 6 × 1 = 1,990
Hexadecimal
7 c 6
7 × 256 + c × 16 + 6 × 1 = 1,990
Read as powers of two: 1,024 + 512 + 256 + 128 + 64 + 4 + 2 = 1,990.
In historical numeral systems
Egyptian
1 lotus, 9 coils of rope, 9 hobbles
1 × 1,000 + 9 × 100 + 9 × 10 = 1,990. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
3 corner wedges + 3 vertical wedges (sixties place), 1 corner wedge (units place)
33 × 60 + 10 = 1990. 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
1990 is a year in the 20th century, in the 1990s.
Hubble launched in 1990 and Webb in 2021. Webb observes in the infrared and had to unfold itself after launch with no possibility of the repair missions Hubble depended on.
View 2021 →History
In 1990, the Hubble Space Telescope was launched, and Nelson Mandela was released from prison.
DocumentedHistoryGeography: globalPeriod: 1990German reunification completed within a year of the Berlin Wall opening, well ahead of any prepared timetable. Mandela's release in February 1990 began the negotiations that produced South Africa's first democratic election four years later.
DocumentedHistoryPeriod: 1990
Science
In 1990, The Hubble Space Telescope was launched, and its mirror was found to be misground before a servicing mission corrected it.
DocumentedScienceGeography: globalPeriod: 1990
Common questions
Is 1990 a prime number?
No, 1990 is not prime.
What are the factors of 1990?
The factors of 1990 are 1, 2, 5, 10, 199, 398, 995, 1990.
What is 1990 in Roman numerals?
1990 in Roman numerals is MCMXC. XC is subtractive: ten before a hundred — a hundred minus ten. Written additively it would be MDCCCCLXXXX, 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