1240
1240 is a year in the 13th century. Kyiv was sacked by the Mongols, ending Kievan Rus as a power (Eastern Europe).
- Even
- Composite
Where 1240 fits
Why 1240 is special
1240 has a profile because of what happened in it rather than because of any property of the number: Kyiv was sacked by the Mongols, ending Kievan Rus as a power (Eastern Europe).
1240 is part of
Factors & digit properties
- Divisors (16)
- 1, 2, 4, 5, 8, 10, 20, 31, 40, 62, 124, 155, 248, 310, 620, 1240
- Prime factorisation
- 2^3 × 5 × 31
- Digit sum
- 7
- Digital root
- 7
Representations
- Decimal
- 1240
- Scientific notation
- 1.240 × 10^3
Roman numerals
M C C X L
MCCXL uses the subtractive pair XL: ten before fifty — fifty minus ten.
Binary
1 0 0 1 1 0 1 1 0 0 0
1 × 1,024 + 0 × 512 + 0 × 256 + 1 × 128 + 1 × 64 + 0 × 32 + 1 × 16 + 1 × 8 + 0 × 4 + 0 × 2 + 0 × 1 = 1,240
Octal
2 3 3 0
2 × 512 + 3 × 64 + 3 × 8 + 0 × 1 = 1,240
Hexadecimal
4 d 8
4 × 256 + d × 16 + 8 × 1 = 1,240
Read as powers of two: 1,024 + 128 + 64 + 16 + 8 = 1,240.
In historical numeral systems
Egyptian
1 lotus, 2 coils of rope, 4 hobbles
1 × 1,000 + 2 × 100 + 4 × 10 = 1,240. 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), 4 corner wedges (units place)
20 × 60 + 40 = 1240. 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
- Abundant number
Related numbers & connections
1240 is a year in the 13th century, in the 1240s.
Numbers Around Us
- appears inHistorical years
why?
Strength 0.50, confidence "high".
History
In 1240, Kyiv was sacked by the Mongols, ending Kievan Rus as a power (Eastern Europe).
DocumentedHistoryGeography: Eastern EuropePeriod: 1240
Common questions
Is 1240 a prime number?
No, 1240 is not prime.
What are the factors of 1240?
The factors of 1240 are 1, 2, 4, 5, 8, 10, 20, 31, 40, 62, 124, 155, 248, 310, 620, 1240.
What is 1240 in Roman numerals?
1240 in Roman numerals is MCCXL. XL is subtractive: ten before fifty — fifty minus ten. Written additively it would be MCCXXXX, 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