242
+242 is the international calling code for Republic of the Congo.
- Even
- Composite
Where 242 fits
Why 242 is special
Two neighbouring countries are both called Congo, distinguished in practice by their capitals — Brazzaville here, Kinshasa across the river. Their calling codes, +242 and +243, are one of the few unambiguous ways to tell them apart.
242 is part of
Factors & digit properties
- Divisors (6)
- 1, 2, 11, 22, 121, 242
- Prime factorisation
- 2 × 11^2
- Digit sum
- 8
- Digital root
- 8
Representations
- Decimal
- 242
- Scientific notation
- 2.420 × 10^2
Roman numerals
C C X L I I
CCXLII uses the subtractive pair XL: ten before fifty — fifty minus ten.
Binary
1 1 1 1 0 0 1 0
1 × 128 + 1 × 64 + 1 × 32 + 1 × 16 + 0 × 8 + 0 × 4 + 1 × 2 + 0 × 1 = 242
Octal
3 6 2
3 × 64 + 6 × 8 + 2 × 1 = 242
Hexadecimal
f 2
f × 16 + 2 × 1 = 242
Read as powers of two: 128 + 64 + 32 + 16 + 2 = 242.
In historical numeral systems
Egyptian
2 coils of rope, 4 hobbles, 2 strokes
2 × 100 + 4 × 10 + 2 × 1 = 242. 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), 2 vertical wedges (units place)
4 × 60 + 2 = 242. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
sigma, then mu, then beta, marked as a numeral
sigma-mu-beta + keraia
sigma + 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
resh, then mem, then bet
resh-mem-bet
resh (200) + mem (40) + bet (2) = 242, written in descending order.
Maya
2 bars + 2 dots (upper, twenties place) over 2 dots (lower, units place)
12 × 20 + 2 = 242. 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
- Palindromic number
- Deficient number
Related numbers & connections
Gabon and the Republic of the Congo share a border and both sit in the Congo Basin, the second-largest rainforest on Earth.
View 241 →Geography
+242 reaches the Republic of the Congo. Its capital Brazzaville and Kinshasa in the Democratic Republic of the Congo face each other across the river — the closest pair of capital cities in the world, in two different countries.
DocumentedGeographyGeography: Republic of the Congo
Common questions
Is 242 a prime number?
No, 242 is not prime.
What are the factors of 242?
The factors of 242 are 1, 2, 11, 22, 121, 242.
What is 242 in Roman numerals?
242 in Roman numerals is CCXLII. XL is subtractive: ten before fifty — fifty minus ten. Written additively it would be CCXXXXII, 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