4015
4015 Wilson-Harrington was recorded as a comet and then lost.
- Odd
- Composite
Where 4015 fits
Why 4015 is special
It was found again forty years later as an asteroid before anyone realised the two objects were the same, which is why it holds both designations.
Factors & digit properties
- Divisors (8)
- 1, 5, 11, 55, 73, 365, 803, 4015
- Prime factorisation
- 5 × 11 × 73
- Digit sum
- 10
- Digital root
- 1
Representations
- Decimal
- 4015
- Scientific notation
- 4.015 × 10^3
Roman numerals
Roman numerals as modelled here goes up to 3,999.
Binary
1 1 1 1 1 0 1 0 1 1 1 1
1 × 2,048 + 1 × 1,024 + 1 × 512 + 1 × 256 + 1 × 128 + 0 × 64 + 1 × 32 + 0 × 16 + 1 × 8 + 1 × 4 + 1 × 2 + 1 × 1 = 4,015
Octal
7 6 5 7
7 × 512 + 6 × 64 + 5 × 8 + 7 × 1 = 4,015
Hexadecimal
f a f
f × 256 + a × 16 + f × 1 = 4,015
Read as powers of two: 2,048 + 1,024 + 512 + 256 + 128 + 32 + 8 + 4 + 2 + 1 = 4,015.
In historical numeral systems
Egyptian
4 lotuses, 1 hobble, 5 strokes
4 × 1,000 + 1 × 10 + 5 × 1 = 4,015. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
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
- Lucky number (mathematical sieve)
Related numbers & connections
Both blur the asteroid-comet distinction, one by being catalogued twice and one by orbiting inside the belt.
View 7968 →Numbers Around Us
- appears alongside7968
why?
Strength 0.50, confidence "high".
Science
4015 Wilson-Harrington was observed with a tail in 1949, lost, and rediscovered as an apparently inactive asteroid in 1979. The identification of the two as one object came later.
DocumentedSciencePeriod: 1949–
Common questions
Is 4015 a prime number?
No, 4015 is not prime.
What are the factors of 4015?
The factors of 4015 are 1, 5, 11, 55, 73, 365, 803, 4015.
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