142
E142 is Green S.
- Even
- Composite
Where 142 fits
Why 142 is special
It is a synthetic green used where the plant-derived colours will not survive processing, and it is banned in several countries.
Factors & digit properties
- Divisors (4)
- 1, 2, 71, 142
- Prime factorisation
- 2 × 71
- Digit sum
- 7
- Digital root
- 7
Representations
- Decimal
- 142
- Scientific notation
- 1.420 × 10^2
Roman numerals
C X L I I
CXLII uses the subtractive pair XL: ten before fifty — fifty minus ten.
Binary
1 0 0 0 1 1 1 0
1 × 128 + 0 × 64 + 0 × 32 + 0 × 16 + 1 × 8 + 1 × 4 + 1 × 2 + 0 × 1 = 142
Octal
2 1 6
2 × 64 + 1 × 8 + 6 × 1 = 142
Hexadecimal
8 e
8 × 16 + e × 1 = 142
Read as powers of two: 128 + 8 + 4 + 2 = 142.
In historical numeral systems
Egyptian
1 coil of rope, 4 hobbles, 2 strokes
1 × 100 + 4 × 10 + 2 × 1 = 142. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
2 vertical wedges (sixties place), 2 corner wedges + 2 vertical wedges (units place)
2 × 60 + 22 = 142. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
rho, then mu, then beta, marked as a numeral
rho-mu-beta + keraia
rho + mu + beta written in descending order and added — the letters carry their values wherever they stand, so this is addition, not place value.
Hebrew numerals
qof, then mem, then bet
qof-mem-bet
qof (100) + mem (40) + bet (2) = 142, written in descending order.
Maya
1 bar + 2 dots (upper, twenties place) over 2 dots (lower, units place)
7 × 20 + 2 = 142. Places stack vertically with the smallest at the bottom, so the upper group is worth twenty times the lower.
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
- Semiprime
Related numbers & connections
One green comes from plants and will not hold its colour; the other is synthetic and does.
View 140 →Everyday life
E142 Green S is a synthetic triarylmethane dye used where chlorophyll-based colours are insufficiently stable. It is prohibited in several jurisdictions.
DocumentedEveryday lifeGeography: European Union and states adopting the E number systemPeriod: 1962–
Common questions
Is 142 a prime number?
No, 142 is not prime.
What are the factors of 142?
The factors of 142 are 1, 2, 71, 142.
What is 142 in Roman numerals?
142 in Roman numerals is CXLII. XL is subtractive: ten before fifty — fifty minus ten. Written additively it would be CXXXXII, 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: 1 reviewer-confirmed record, sourced and reviewed before publication.
Last reviewed: 15 July 2026