389
Port 389 carries LDAP, the directory protocol behind most corporate logins.
- Odd
- Prime
Where 389 fits
Why 389 is special
When a work laptop accepts a password, an LDAP directory is usually what confirmed it. Port 389 is the unencrypted form and 636 the TLS one, which is why directory traffic on 389 inside a corporate network is a long-standing audit finding.
389 is part of
Factors & digit properties
- Divisors (2)
- 1, 389
- Prime factorisation
- 389
- Digit sum
- 20
- Digital root
- 2
Representations
- Decimal
- 389
- Scientific notation
- 3.890 × 10^2
Roman numerals
C C C L X X X I X
CCCLXXXIX uses the subtractive pair IX: one before ten — ten minus one.
Binary
1 1 0 0 0 0 1 0 1
1 × 256 + 1 × 128 + 0 × 64 + 0 × 32 + 0 × 16 + 0 × 8 + 1 × 4 + 0 × 2 + 1 × 1 = 389
Octal
6 0 5
6 × 64 + 0 × 8 + 5 × 1 = 389
Hexadecimal
1 8 5
1 × 256 + 8 × 16 + 5 × 1 = 389
Read as powers of two: 256 + 128 + 4 + 1 = 389.
In historical numeral systems
Egyptian
3 coils of rope, 8 hobbles, 9 strokes
3 × 100 + 8 × 10 + 9 × 1 = 389. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
6 vertical wedges (sixties place), 2 corner wedges + 9 vertical wedges (units place)
6 × 60 + 29 = 389. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
tau, then pi, then theta, marked as a numeral
tau-pi-theta + keraia
tau + pi + theta written in descending order and added — the letters carry their values wherever they stand, so this is addition, not place value.
Hebrew numerals
shin, then pe, then tet
shin-pe-tet
shin (300) + pe (80) + tet (9) = 389, written in descending order.
Maya
3 bars + 4 dots (upper, twenties place) over 1 bar + 4 dots (lower, units place)
19 × 20 + 9 = 389. 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
Related numbers & connections
LDAP runs on port 389 in the clear and 636 under TLS, a split that predates the assumption that directory queries should be encrypted.
View 4511 →Technology & computing
LDAP directories are what most corporate logins are verified against. Port 389 carries it unencrypted and 636 carries it over TLS, which is why directory traffic on 389 remains a standing audit finding even on internal networks.
DocumentedTechnology & computing
Common questions
Is 389 a prime number?
Yes, 389 is prime — it has exactly two positive divisors: 1 and itself.
What are the factors of 389?
The factors of 389 are 1, 389.
What is 389 in Roman numerals?
389 in Roman numerals is CCCLXXXIX. IX is subtractive: one before ten — ten minus one. Written additively it would be CCCLXXXVIIII, 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