423
HTTP 423 Locked means the resource is locked against the requested change.
- Odd
- Composite
Where 423 fits
Why 423 is special
423 comes from WebDAV, where a client can take an explicit lock on a document before editing it. It is the check-out model applied to HTTP: the second editor is refused outright rather than allowed to start work that will later conflict.
Not just a mathematical number
423is also used in ways where ordinary arithmetic doesn't apply — each listed below with what genuinely does and doesn't follow from it.
- Mathematical number
A genuine quantity — its mathematical properties (prime, square, factors, and so on) are real facts about it.
A genuine quantity that ordinary arithmetic applies to — it can be prime, even, a perfect square, added to another number meaningfully, and so on.
- Code
Also used as a code — HTTP status codes.
An assigned identifier from a fixed registry or standard — its digits don't represent an amount, and arithmetic on it is meaningless (HTTP status 404 + 1 is not a 'better' status; it's a different, unrelated code).
Factors & digit properties
- Divisors (6)
- 1, 3, 9, 47, 141, 423
- Prime factorisation
- 3^2 × 47
- Digit sum
- 9
- Digital root
- 9
Representations
- Decimal
- 423
- Scientific notation
- 4.230 × 10^2
Roman numerals
C D X X I I I
CDXXIII uses the subtractive pair CD: a hundred before five hundred — five hundred minus a hundred.
Binary
1 1 0 1 0 0 1 1 1
1 × 256 + 1 × 128 + 0 × 64 + 1 × 32 + 0 × 16 + 0 × 8 + 1 × 4 + 1 × 2 + 1 × 1 = 423
Octal
6 4 7
6 × 64 + 4 × 8 + 7 × 1 = 423
Hexadecimal
1 a 7
1 × 256 + a × 16 + 7 × 1 = 423
Read as powers of two: 256 + 128 + 32 + 4 + 2 + 1 = 423.
In historical numeral systems
Egyptian
4 coils of rope, 2 hobbles, 3 strokes
4 × 100 + 2 × 10 + 3 × 1 = 423. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
7 vertical wedges (sixties place), 3 vertical wedges (units place)
7 × 60 + 3 = 423. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
upsilon, then kappa, then gamma, marked as a numeral
upsilon-kappa-gamma + keraia
upsilon + kappa + gamma 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 kaf, then gimel
tav-kaf-gimel
tav (400) + kaf (20) + gimel (3) = 423, 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
Related numbers & connections
423 refuses a change because the resource is explicitly locked, a WebDAV mechanism that applies a check-out model to HTTP.
Numbers Around Us
- appears inHTTP status codes
why?
Strength 0.50, confidence "high".
Technology & computing
423 comes from WebDAV, where a client can lock a document before editing it. It applies the check-out model to HTTP: rather than letting two people edit and resolving the conflict afterwards, the second is refused at the point of asking.
DocumentedTechnology & computing
Common questions
Is 423 a prime number?
No, 423 is not prime.
What are the factors of 423?
The factors of 423 are 1, 3, 9, 47, 141, 423.
What is 423 in Roman numerals?
423 in Roman numerals is CDXXIII. CD is subtractive: a hundred before five hundred — five hundred minus a hundred. Written additively it would be CCCCXXIII, 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