122
122 is the year construction began on Hadrian's Wall.
- Even
- Composite
Where 122 fits
Why 122 is special
It ran 117 km across northern Britain and took about six years. Whether it was primarily military, a customs frontier or a statement of imperial limit is still argued.
Factors & digit properties
- Divisors (4)
- 1, 2, 61, 122
- Prime factorisation
- 2 × 61
- Digit sum
- 5
- Digital root
- 5
Representations
- Decimal
- 122
- Scientific notation
- 1.220 × 10^2
Roman numerals
C X X I I
Binary
1 1 1 1 0 1 0
1 × 64 + 1 × 32 + 1 × 16 + 1 × 8 + 0 × 4 + 1 × 2 + 0 × 1 = 122
Octal
1 7 2
1 × 64 + 7 × 8 + 2 × 1 = 122
Hexadecimal
7 a
7 × 16 + a × 1 = 122
Read as powers of two: 64 + 32 + 16 + 8 + 2 = 122.
In historical numeral systems
Egyptian
1 coil of rope, 2 hobbles, 2 strokes
1 × 100 + 2 × 10 + 2 × 1 = 122. 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 vertical wedges (units place)
2 × 60 + 2 = 122. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
rho, then kappa, then beta, marked as a numeral
rho-kappa-beta + keraia
rho + kappa + 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 kaf, then bet
qof-kaf-bet
qof (100) + kaf (20) + bet (2) = 122, written in descending order.
Maya
1 bar + 1 dot (upper, twenties place) over 2 dots (lower, units place)
6 × 20 + 2 = 122. 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
Hadrian's Wall was begun in 122 as the northern limit of Roman Britain, and Rome itself was sacked in 410 — the frontier outlasted the confidence that built it by less than three centuries.
View 410 →Other connections
- is associated with410
why?
Strength 0.50, confidence "high".
History
Hadrian's Wall was built from 122 across the width of Britain. Its function — defence, taxation, or a declaration that the empire ended here — remains a live question among archaeologists.
DocumentedHistoryGeography: BritainPeriod: 122
Common questions
Is 122 a prime number?
No, 122 is not prime.
What are the factors of 122?
The factors of 122 are 1, 2, 61, 122.
What is 122 in Roman numerals?
122 in Roman numerals is CXXII.
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