1211
1211 is a year in the 13th century. The Mongol invasion of the Jin empire began (China).
- Odd
- Composite
Where 1211 fits
Why 1211 is special
1211 has a profile because of what happened in it rather than because of any property of the number: the Mongol invasion of the Jin empire began (China).
1211 is part of
Factors & digit properties
- Divisors (4)
- 1, 7, 173, 1211
- Prime factorisation
- 7 × 173
- Digit sum
- 5
- Digital root
- 5
Representations
- Decimal
- 1211
- Scientific notation
- 1.211 × 10^3
Roman numerals
M C C X I
Binary
1 0 0 1 0 1 1 1 0 1 1
1 × 1,024 + 0 × 512 + 0 × 256 + 1 × 128 + 0 × 64 + 1 × 32 + 1 × 16 + 1 × 8 + 0 × 4 + 1 × 2 + 1 × 1 = 1,211
Octal
2 2 7 3
2 × 512 + 2 × 64 + 7 × 8 + 3 × 1 = 1,211
Hexadecimal
4 b b
4 × 256 + b × 16 + b × 1 = 1,211
Read as powers of two: 1,024 + 128 + 32 + 16 + 8 + 2 + 1 = 1,211.
In historical numeral systems
Egyptian
1 lotus, 2 coils of rope, 1 hobble, 1 stroke
1 × 1,000 + 2 × 100 + 1 × 10 + 1 × 1 = 1,211. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
2 corner wedges (sixties place), 1 corner wedge + 1 vertical wedge (units place)
20 × 60 + 11 = 1211. Places are separated by a space on the tablet, with the higher place written first.
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
- Happy number
- Semiprime
Related numbers & connections
1211 is a year in the 13th century, in the 1210s.
Numbers Around Us
- appears inHistorical years
why?
Strength 0.50, confidence "high".
History
In 1211, the Mongol invasion of the Jin empire began (China).
DocumentedHistoryGeography: ChinaPeriod: 1211
Common questions
Is 1211 a prime number?
No, 1211 is not prime.
What are the factors of 1211?
The factors of 1211 are 1, 7, 173, 1211.
What is 1211 in Roman numerals?
1211 in Roman numerals is MCCXI.
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