667
D. 667 is the Trout Quintet.
- Odd
- Composite
Where 667 fits
Why 667 is special
Its unusual scoring includes a double bass instead of a second violin, which was specified by the amateur cellist who commissioned it.
Factors & digit properties
- Divisors (4)
- 1, 23, 29, 667
- Prime factorisation
- 23 × 29
- Digit sum
- 19
- Digital root
- 1
Representations
- Decimal
- 667
- Scientific notation
- 6.670 × 10^2
Roman numerals
D C L X V I I
Binary
1 0 1 0 0 1 1 0 1 1
1 × 512 + 0 × 256 + 1 × 128 + 0 × 64 + 0 × 32 + 1 × 16 + 1 × 8 + 0 × 4 + 1 × 2 + 1 × 1 = 667
Octal
1 2 3 3
1 × 512 + 2 × 64 + 3 × 8 + 3 × 1 = 667
Hexadecimal
2 9 b
2 × 256 + 9 × 16 + b × 1 = 667
Read as powers of two: 512 + 128 + 16 + 8 + 2 + 1 = 667.
In historical numeral systems
Egyptian
6 coils of rope, 6 hobbles, 7 strokes
6 × 100 + 6 × 10 + 7 × 1 = 667. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
1 corner wedge + 1 vertical wedge (sixties place), 7 vertical wedges (units place)
11 × 60 + 7 = 667. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
chi, then xi, then zeta, marked as a numeral
chi-xi-zeta + keraia
chi + xi + zeta written in descending order and added — the letters carry their values wherever they stand, so this is addition, not place value.
Hebrew numerals
tav, then resh, then samekh, then zayin
tav-resh-samekh-zayin
tav (400) + resh (200) + samekh (60) + zayin (7) = 667, written in descending order.
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
Both take their names from Schubert songs whose melodies they vary.
View 810 →Media & popular culture
D. 667 is scored for piano, violin, viola, cello and double bass, an arrangement requested by the commissioner Sylvester Paumgartner. The fourth movement varies Schubert's song Die Forelle.
DocumentedMedia & popular cultureGeography: AustriaPeriod: 1819
Common questions
Is 667 a prime number?
No, 667 is not prime.
What are the factors of 667?
The factors of 667 are 1, 23, 29, 667.
What is 667 in Roman numerals?
667 in Roman numerals is DCLXVII.
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