1930
1930 is the year Pluto was discovered.
- Even
- Composite
Where 1930 fits
Why 1930 is special
It was found by a 24-year-old comparing photographic plates for a tiny shifting dot. The prediction that led to the search was based on calculation errors, so Pluto was found in roughly the right place for entirely the wrong reasons.
1930 is part of
Factors & digit properties
- Divisors (8)
- 1, 2, 5, 10, 193, 386, 965, 1930
- Prime factorisation
- 2 × 5 × 193
- Digit sum
- 13
- Digital root
- 4
Representations
- Decimal
- 1930
- Scientific notation
- 1.930 × 10^3
Roman numerals
M C M X X X
MCMXXX uses the subtractive pair CM: a hundred before a thousand — a thousand minus a hundred.
Binary
1 1 1 1 0 0 0 1 0 1 0
1 × 1,024 + 1 × 512 + 1 × 256 + 1 × 128 + 0 × 64 + 0 × 32 + 0 × 16 + 1 × 8 + 0 × 4 + 1 × 2 + 0 × 1 = 1,930
Octal
3 6 1 2
3 × 512 + 6 × 64 + 1 × 8 + 2 × 1 = 1,930
Hexadecimal
7 8 a
7 × 256 + 8 × 16 + a × 1 = 1,930
Read as powers of two: 1,024 + 512 + 256 + 128 + 8 + 2 = 1,930.
In historical numeral systems
Egyptian
1 lotus, 9 coils of rope, 3 hobbles
1 × 1,000 + 9 × 100 + 3 × 10 = 1,930. 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), 1 corner wedge (units place)
32 × 60 + 10 = 1930. 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
- Happy number
Related numbers & connections
1930 is a year in the 20th century, in the 1930s.
Ceres was found in 1801 and called a planet, then an asteroid, then a dwarf planet; Pluto was found in 1930 and reclassified in 2006. Neither object changed.
View 1801 →Science
In 1930, Pluto was discovered at Lowell Observatory (North America).
DocumentedScienceGeography: North AmericaPeriod: 1930The search that located Pluto was driven by supposed irregularities in Neptune's orbit that turned out not to exist. Clyde Tombaugh found a real object near the predicted position anyway, which makes the discovery genuine and the prediction spurious.
DocumentedSciencePeriod: 1930
Common questions
Is 1930 a prime number?
No, 1930 is not prime.
What are the factors of 1930?
The factors of 1930 are 1, 2, 5, 10, 193, 386, 965, 1930.
What is 1930 in Roman numerals?
1930 in Roman numerals is MCMXXX. CM is subtractive: a hundred before a thousand — a thousand minus a hundred. Written additively it would be MDCCCCXXX, 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