209
CWE-209 is information exposure through an error message.
- Odd
- Composite
Where 209 fits
Why 209 is special
A stack trace on a production page tells an attacker the framework, the version, the file paths and often the database schema.
Factors & digit properties
- Divisors (4)
- 1, 11, 19, 209
- Prime factorisation
- 11 × 19
- Digit sum
- 11
- Digital root
- 2
Representations
- Decimal
- 209
- Scientific notation
- 2.090 × 10^2
Roman numerals
C C I X
CCIX uses the subtractive pair IX: one before ten — ten minus one.
Binary
1 1 0 1 0 0 0 1
1 × 128 + 1 × 64 + 0 × 32 + 1 × 16 + 0 × 8 + 0 × 4 + 0 × 2 + 1 × 1 = 209
Octal
3 2 1
3 × 64 + 2 × 8 + 1 × 1 = 209
Hexadecimal
d 1
d × 16 + 1 × 1 = 209
Read as powers of two: 128 + 64 + 16 + 1 = 209.
In historical numeral systems
Egyptian
2 coils of rope, 9 strokes
2 × 100 + 9 × 1 = 209. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
3 vertical wedges (sixties place), 2 corner wedges + 9 vertical wedges (units place)
3 × 60 + 29 = 209. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
sigma, then theta, marked as a numeral
sigma-theta + keraia
sigma + theta written in descending order and added — the letters carry their values wherever they stand, so this is addition, not place value.
Hebrew numerals
resh, then tet
resh-tet
resh (200) + tet (9) = 209, written in descending order.
Maya
2 bars (upper, twenties place) over 1 bar + 4 dots (lower, units place)
10 × 20 + 9 = 209. Places stack vertically with the smallest at the bottom, so the upper group is worth twenty times the lower.
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
- Harshad (Niven) number
Related numbers & connections
An error page and a log file leak the same internal detail to different audiences.
View 532 →Numbers Around Us
- appears alongside532
why?
Strength 0.50, confidence "high".
Technology & computing
CWE-209 covers error messages disclosing internal state such as stack traces, file paths, query fragments or version details to unauthorised users.
DocumentedTechnology & computingGeography: International — MITRE CWEPeriod: 2006–
Common questions
Is 209 a prime number?
No, 209 is not prime.
What are the factors of 209?
The factors of 209 are 1, 11, 19, 209.
What is 209 in Roman numerals?
209 in Roman numerals is CCIX. IX is subtractive: one before ten — ten minus one. Written additively it would be CCVIIII, 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