551
551 BC is the traditional birth year of Confucius.
- Odd
- Composite
Where 551 fits
Why 551 is special
His teaching on duty, hierarchy and government shaped Chinese, Korean, Japanese and Vietnamese administration for two millennia, largely through examination systems built on his texts.
Same number, different meanings
How 551 is understood across different contexts — never implying one meaning because of another.
- Mathematics
His teaching on duty, hierarchy and government shaped Chinese, Korean, Japanese and Vietnamese administration for two millennia, largely through examination systems built on his texts.
- Culture
Confucian texts became the syllabus for imperial examinations, so a body of ethical teaching determined who governed across East Asia for centuries. Few philosophies have been institutionalised that directly.
- Media & popular culture
K. 551 was Mozart's last symphony, and its finale combines five themes in simultaneous counterpoint in the closing bars.
Factors & digit properties
- Divisors (4)
- 1, 19, 29, 551
- Prime factorisation
- 19 × 29
- Digit sum
- 11
- Digital root
- 2
Representations
- Decimal
- 551
- Scientific notation
- 5.510 × 10^2
Roman numerals
D L I
Binary
1 0 0 0 1 0 0 1 1 1
1 × 512 + 0 × 256 + 0 × 128 + 0 × 64 + 1 × 32 + 0 × 16 + 0 × 8 + 1 × 4 + 1 × 2 + 1 × 1 = 551
Octal
1 0 4 7
1 × 512 + 0 × 64 + 4 × 8 + 7 × 1 = 551
Hexadecimal
2 2 7
2 × 256 + 2 × 16 + 7 × 1 = 551
Read as powers of two: 512 + 32 + 4 + 2 + 1 = 551.
In historical numeral systems
Egyptian
5 coils of rope, 5 hobbles, 1 stroke
5 × 100 + 5 × 10 + 1 × 1 = 551. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
9 vertical wedges (sixties place), 1 corner wedge + 1 vertical wedge (units place)
9 × 60 + 11 = 551. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
phi, then nu, then alpha, marked as a numeral
phi-nu-alpha + keraia
phi + nu + alpha 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 qof, then nun, then alef
tav-qof-nun-alef
tav (400) + qof (100) + nun (50) + alef (1) = 551, 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
The traditional birth years of the Buddha and Confucius fall within a dozen years of each other, and both produced systems that shaped the administration of large parts of Asia for two millennia.
View 563 →Numbers Around Us
- appears alongside563
why?
Strength 0.50, confidence "high".
Culture
Confucian texts became the syllabus for imperial examinations, so a body of ethical teaching determined who governed across East Asia for centuries. Few philosophies have been institutionalised that directly.
DocumentedCultureGeography: ChinaPeriod: around 551 BC
Media & popular culture
K. 551 was Mozart's last symphony, and its finale combines five themes in simultaneous counterpoint in the closing bars.
DocumentedMedia & popular cultureGeography: AustriaPeriod: 1788
Common questions
Is 551 a prime number?
No, 551 is not prime.
What are the factors of 551?
The factors of 551 are 1, 19, 29, 551.
What is 551 in Roman numerals?
551 in Roman numerals is DLI.
About this page's data
Mathematical facts:computed directly from the number's value — nothing to source or verify externally.
Contextual records: 2 reviewer-confirmed records, sourced and reviewed before publication.
Last reviewed: 15 July 2026