12,742
Earth's mean diameter is about 12,742 km.
- Even
- Composite
Where 12,742 fits
Why 12,742 is special
A useful check on the figure: the metre was defined so that the pole-to-equator distance is ten million metres, which makes the circumference 40,000 km, and dividing by pi gives 12,732 — within a tenth of a percent of the real value.
Factors & digit properties
- Divisors (8)
- 1, 2, 23, 46, 277, 554, 6371, 12742
- Prime factorisation
- 2 × 23 × 277
- Digit sum
- 16
- Digital root
- 7
Representations
- Decimal
- 12742
- Scientific notation
- 1.274 × 10^4
Roman numerals
Roman numerals as modelled here goes up to 3,999.
Binary
1 1 0 0 0 1 1 1 0 0 0 1 1 0
1 × 8,192 + 1 × 4,096 + 0 × 2,048 + 0 × 1,024 + 0 × 512 + 1 × 256 + 1 × 128 + 1 × 64 + 0 × 32 + 0 × 16 + 0 × 8 + 1 × 4 + 1 × 2 + 0 × 1 = 12,742
Octal
3 0 7 0 6
3 × 4,096 + 0 × 512 + 7 × 64 + 0 × 8 + 6 × 1 = 12,742
Hexadecimal
3 1 c 6
3 × 4,096 + 1 × 256 + c × 16 + 6 × 1 = 12,742
Read as powers of two: 8,192 + 4,096 + 256 + 128 + 64 + 4 + 2 = 12,742.
In historical numeral systems
Egyptian
1 finger, 2 lotuses, 7 coils of rope, 4 hobbles, 2 strokes
1 × 10,000 + 2 × 1,000 + 7 × 100 + 4 × 10 + 2 × 1 = 12,742. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
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
The mean diameter is twice the mean radius, and both can be checked against the definition of the metre — which put the pole-to-equator distance at ten million metres.
View 6378 →Mathematically related
- is a multiple of6378
why?
Strength 0.50, confidence "high".
Geography
Earth averages about 12,742 km across. The metre was defined to make the pole-to-equator distance ten million metres, so the circumference is 40,000 km and dividing by pi gives 12,732 — within a tenth of a percent of the measured value.
DocumentedGeography
Common questions
Is 12,742 a prime number?
No, 12,742 is not prime.
What are the factors of 12,742?
The factors of 12,742 are 1, 2, 23, 46, 277, 554, 6371, 12742.
About this page's data
Mathematical facts:computed directly from the number's value — nothing to source or verify externally.
Contextual records: 1 reviewer-confirmed record, sourced and reviewed before publication.
Last reviewed: 15 July 2026