290
+290 is the international calling code for Saint Helena.
- Even
- Composite
Where 290 fits
Why 290 is special
Saint Helena is among the most remote inhabited islands on Earth and had no airport until 2016, relying on a Royal Mail ship for all access.
Factors & digit properties
- Divisors (8)
- 1, 2, 5, 10, 29, 58, 145, 290
- Prime factorisation
- 2 × 5 × 29
- Digit sum
- 11
- Digital root
- 2
Representations
- Decimal
- 290
- Scientific notation
- 2.900 × 10^2
Roman numerals
C C X C
CCXC uses the subtractive pair XC: ten before a hundred — a hundred minus ten.
Binary
1 0 0 1 0 0 0 1 0
1 × 256 + 0 × 128 + 0 × 64 + 1 × 32 + 0 × 16 + 0 × 8 + 0 × 4 + 1 × 2 + 0 × 1 = 290
Octal
4 4 2
4 × 64 + 4 × 8 + 2 × 1 = 290
Hexadecimal
1 2 2
1 × 256 + 2 × 16 + 2 × 1 = 290
Read as powers of two: 256 + 32 + 2 = 290.
In historical numeral systems
Egyptian
2 coils of rope, 9 hobbles
2 × 100 + 9 × 10 = 290. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
4 vertical wedges (sixties place), 5 corner wedges (units place)
4 × 60 + 50 = 290. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
sigma, then koppa, marked as a numeral
sigma-koppa + keraia
sigma + koppa written in descending order and added — the letters carry their values wherever they stand, so this is addition, not place value.
Hebrew numerals
resh, then tsadi
resh-tsadi
resh (200) + tsadi (90) = 290, written in descending order.
Maya
2 bars + 4 dots (upper, twenties place) over 2 bars (lower, units place)
14 × 20 + 10 = 290. 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
Related numbers & connections
Ascension and Saint Helena are administered together and are among the remotest inhabited places on Earth. Saint Helena had no airport until 2016.
View 247 →Other connections
- is associated with247
why?
Strength 0.50, confidence "high".
Geography
+290 reaches Saint Helena, which depended on a scheduled ship for every arrival and departure until an airport opened in 2016 — delayed because wind shear made the first runway unusable.
DocumentedGeographyGeography: Saint Helena
Common questions
Is 290 a prime number?
No, 290 is not prime.
What are the factors of 290?
The factors of 290 are 1, 2, 5, 10, 29, 58, 145, 290.
What is 290 in Roman numerals?
290 in Roman numerals is CCXC. XC is subtractive: ten before a hundred — a hundred minus ten. Written additively it would be CCLXXXX, 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