621
621 BC is the year of Draco's law code in Athens.
- Odd
- Composite
Where 621 fits
Why 621 is special
The penalties were so severe that the word draconian derives from his name. A later reformer replaced almost all of them, keeping only the homicide provisions.
Same number, different meanings
How 621 is understood across different contexts — never implying one meaning because of another.
- Mathematics
The penalties were so severe that the word draconian derives from his name. A later reformer replaced almost all of them, keeping only the homicide provisions.
- Everyday life
E621 monosodium glutamate has been the subject of controlled trials that have not reproduced the symptom cluster attributed to it. Glutamate occurs naturally in tomatoes, cheese and seaweed.
- Law & regulation
Draco's code of 621 BC prescribed death for a very wide range of offences and gave English the word draconian. Solon repealed nearly all of it within thirty years, retaining only the homicide law.
621 is part of
Factors & digit properties
- Divisors (8)
- 1, 3, 9, 23, 27, 69, 207, 621
- Prime factorisation
- 3^3 × 23
- Digit sum
- 9
- Digital root
- 9
Representations
- Decimal
- 621
- Scientific notation
- 6.210 × 10^2
Roman numerals
D C X X I
Binary
1 0 0 1 1 0 1 1 0 1
1 × 512 + 0 × 256 + 0 × 128 + 1 × 64 + 1 × 32 + 0 × 16 + 1 × 8 + 1 × 4 + 0 × 2 + 1 × 1 = 621
Octal
1 1 5 5
1 × 512 + 1 × 64 + 5 × 8 + 5 × 1 = 621
Hexadecimal
2 6 d
2 × 256 + 6 × 16 + d × 1 = 621
Read as powers of two: 512 + 64 + 32 + 8 + 4 + 1 = 621.
In historical numeral systems
Egyptian
6 coils of rope, 2 hobbles, 1 stroke
6 × 100 + 2 × 10 + 1 × 1 = 621. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
1 corner wedge (sixties place), 2 corner wedges + 1 vertical wedge (units place)
10 × 60 + 21 = 621. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
chi, then kappa, then alpha, marked as a numeral
chi-kappa-alpha + keraia
chi + kappa + 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 resh, then kaf, then alef
tav-resh-kaf-alef
tav (400) + resh (200) + kaf (20) + alef (1) = 621, 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
- Harshad (Niven) number
- Lucky number (mathematical sieve)
Related numbers & connections
Disodium guanylate is used with glutamate because the pair is far more effective than either alone.
View 627 →Draco's code of 621 BC prescribed death for most offences; Solon repealed nearly all of it within thirty years, keeping only the homicide law.
View 594 →Everyday life
E621 monosodium glutamate has been the subject of controlled trials that have not reproduced the symptom cluster attributed to it. Glutamate occurs naturally in tomatoes, cheese and seaweed.
DocumentedEveryday lifeGeography: European Union and states adopting the E number systemPeriod: 1962–MSG's association with adverse effects derives largely from a 1968 letter and subsequent press coverage. Double-blind studies have repeatedly failed to reproduce the effect, and glutamate is abundant in ordinary foods.
DocumentedEveryday lifeGeography: European Union and United Kingdom
Law & regulation
Draco's code of 621 BC prescribed death for a very wide range of offences and gave English the word draconian. Solon repealed nearly all of it within thirty years, retaining only the homicide law.
DocumentedLaw & regulationGeography: AthensPeriod: 621 BC
Common questions
Is 621 a prime number?
No, 621 is not prime.
What are the factors of 621?
The factors of 621 are 1, 3, 9, 23, 27, 69, 207, 621.
What is 621 in Roman numerals?
621 in Roman numerals is DCXXI.
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