1040
Form 1040 is the US individual income tax return.
- Even
- Composite
Where 1040 fits
Why 1040 is special
It has been the main personal tax form since 1913, and its number is used in ordinary American speech as a synonym for filing taxes at all. The instructions run to over a hundred pages for a form of two.
1040 connects to:
- 1099 — appears alongside
- historical years — appears in
Same number, different meanings
How 1040 is understood across different contexts — never implying one meaning because of another.
- Mathematics
It has been the main personal tax form since 1913, and its number is used in ordinary American speech as a synonym for filing taxes at all. The instructions run to over a hundred pages for a form of two.
- Technology & computing
In 1040, Bi Sheng developed movable type in baked clay, four centuries before Gutenberg (China).
- Finance & economics
Form 1040 has been the American personal income tax return since 1913, and the number stands in for the act of filing in ordinary speech. Its instructions run past a hundred pages for a form of two, which is itself a fact about the tax code.
1040 is part of
Factors & digit properties
- Divisors (20)
- 1, 2, 4, 5, 8, 10, 13, 16, 20, 26, 40, 52, 65, 80, 104, 130, 208, 260, 520, 1040
- Prime factorisation
- 2^4 × 5 × 13
- Digit sum
- 5
- Digital root
- 5
Representations
- Decimal
- 1040
- Scientific notation
- 1.040 × 10^3
Roman numerals
M X L
MXL uses the subtractive pair XL: ten before fifty — fifty minus ten.
Binary
1 0 0 0 0 0 1 0 0 0 0
1 × 1,024 + 0 × 512 + 0 × 256 + 0 × 128 + 0 × 64 + 0 × 32 + 1 × 16 + 0 × 8 + 0 × 4 + 0 × 2 + 0 × 1 = 1,040
Octal
2 0 2 0
2 × 512 + 0 × 64 + 2 × 8 + 0 × 1 = 1,040
Hexadecimal
4 1 0
4 × 256 + 1 × 16 + 0 × 1 = 1,040
Read as powers of two: 1,024 + 16 = 1,040.
In historical numeral systems
Egyptian
1 lotus, 4 hobbles
1 × 1,000 + 4 × 10 = 1,040. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
1 corner wedge + 7 vertical wedges (sixties place), 2 corner wedges (units place)
17 × 60 + 20 = 1040. 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
- Harshad (Niven) number
Related numbers & connections
Two US tax forms whose numbers are used as ordinary nouns — 1040 for filing at all, 1099 for being a contractor rather than an employee.
View 1099 →Numbers Around Us
- appears alongside1099
why?
Strength 0.50, confidence "high".
- appears inHistorical years
why?
Strength 0.50, confidence "high".
Technology & computing
In 1040, Bi Sheng developed movable type in baked clay, four centuries before Gutenberg (China).
DocumentedTechnology & computingGeography: ChinaPeriod: 1040The Atari 1040ST included MIDI ports as standard, which no competitor did. It became widely used in music studios for sequencing, a role it held well past its commercial life.
DocumentedTechnology & computingGeography: United States and EuropePeriod: 1986–
Finance & economics
Form 1040 has been the American personal income tax return since 1913, and the number stands in for the act of filing in ordinary speech. Its instructions run past a hundred pages for a form of two, which is itself a fact about the tax code.
DocumentedFinance & economicsGeography: United States
Common questions
Is 1040 a prime number?
No, 1040 is not prime.
What are the factors of 1040?
The factors of 1040 are 1, 2, 4, 5, 8, 10, 13, 16, 20, 26, 40, 52, 65, 80, 104, 130, 208, 260, 520, 1040.
What is 1040 in Roman numerals?
1040 in Roman numerals is MXL. XL is subtractive: ten before fifty — fifty minus ten. Written additively it would be MXXXX, 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: 3 reviewer-confirmed records, sourced and reviewed before publication.
Last reviewed: 15 July 2026