211
+211 is the international calling code for South Sudan.
- Odd
- Prime
Where 211 fits
Why 211 is special
South Sudan became the world's newest widely recognised country in 2011 and was assigned +211 on separation from Sudan.
211 is part of
Factors & digit properties
- Divisors (2)
- 1, 211
- Prime factorisation
- 211
- Digit sum
- 4
- Digital root
- 4
Representations
- Decimal
- 211
- Scientific notation
- 2.110 × 10^2
Roman numerals
C C X I
Binary
1 1 0 1 0 0 1 1
1 × 128 + 1 × 64 + 0 × 32 + 1 × 16 + 0 × 8 + 0 × 4 + 1 × 2 + 1 × 1 = 211
Octal
3 2 3
3 × 64 + 2 × 8 + 3 × 1 = 211
Hexadecimal
d 3
d × 16 + 3 × 1 = 211
Read as powers of two: 128 + 64 + 16 + 2 + 1 = 211.
In historical numeral systems
Egyptian
2 coils of rope, 1 hobble, 1 stroke
2 × 100 + 1 × 10 + 1 × 1 = 211. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
3 vertical wedges (sixties place), 3 corner wedges + 1 vertical wedge (units place)
3 × 60 + 31 = 211. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
sigma, then iota, then alpha, marked as a numeral
sigma-iota-alpha + keraia
sigma + iota + alpha 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 yod, then alef
resh-yod-alef
resh (200) + yod (10) + alef (1) = 211, written in descending order.
Maya
2 bars (upper, twenties place) over 2 bars + 1 dot (lower, units place)
10 × 20 + 11 = 211. 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
- Lucky number (mathematical sieve)
Related numbers & connections
South Sudan seceded from Sudan in 2011 and was assigned +211 beside Sudan's +249. The two codes are a record of the most recent successful secession to produce a UN member state.
View 249 →Nearby in a sequence
- is adjacent to249
why?
Strength 0.50, confidence "high".
Geography
+211 reaches South Sudan, allocated when it separated from Sudan in 2011. It is the most recent addition to the country calling code registry.
DocumentedGeographyGeography: South Sudan
Common questions
Is 211 a prime number?
Yes, 211 is prime — it has exactly two positive divisors: 1 and itself.
What are the factors of 211?
The factors of 211 are 1, 211.
What is 211 in Roman numerals?
211 in Roman numerals is CCXI.
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