847
BWV 847 is the C minor prelude and fugue.
- Odd
- Composite
Where 847 fits
Why 847 is special
The Well-Tempered Clavier works through all twenty-four keys, which was a demonstration that a single tuning could serve them all.
847 is part of
Factors & digit properties
- Divisors (6)
- 1, 7, 11, 77, 121, 847
- Prime factorisation
- 7 × 11^2
- Digit sum
- 19
- Digital root
- 1
Representations
- Decimal
- 847
- Scientific notation
- 8.470 × 10^2
Roman numerals
D C C C X L V I I
DCCCXLVII uses the subtractive pair XL: ten before fifty — fifty minus ten.
Binary
1 1 0 1 0 0 1 1 1 1
1 × 512 + 1 × 256 + 0 × 128 + 1 × 64 + 0 × 32 + 0 × 16 + 1 × 8 + 1 × 4 + 1 × 2 + 1 × 1 = 847
Octal
1 5 1 7
1 × 512 + 5 × 64 + 1 × 8 + 7 × 1 = 847
Hexadecimal
3 4 f
3 × 256 + 4 × 16 + f × 1 = 847
Read as powers of two: 512 + 256 + 64 + 8 + 4 + 2 + 1 = 847.
In historical numeral systems
Egyptian
8 coils of rope, 4 hobbles, 7 strokes
8 × 100 + 4 × 10 + 7 × 1 = 847. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
1 corner wedge + 4 vertical wedges (sixties place), 7 vertical wedges (units place)
14 × 60 + 7 = 847. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
omega, then mu, then zeta, marked as a numeral
omega-mu-zeta + keraia
omega + mu + 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 tav, then mem, then zayin
tav-tav-mem-zayin
tav (400) + tav (400) + mem (40) + zayin (7) = 847, 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
- Happy number
Related numbers & connections
The first two preludes and fugues of a collection that works through all twenty-four keys.
View 846 →The Well-Tempered Clavier traverses all twenty-four major and minor keys as a demonstration of tuning.
View 24 →Media & popular culture
BWV 847 is the second prelude and fugue of the first book. The collection traverses all twenty-four major and minor keys, demonstrating the practicability of well temperament.
DocumentedMedia & popular cultureGeography: GermanyPeriod: 1722
Common questions
Is 847 a prime number?
No, 847 is not prime.
What are the factors of 847?
The factors of 847 are 1, 7, 11, 77, 121, 847.
What is 847 in Roman numerals?
847 in Roman numerals is DCCCXLVII. XL is subtractive: ten before fifty — fifty minus ten. Written additively it would be DCCCXXXXVII, 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