27,015
Port 27015 is the default port for Source engine game servers.
- Odd
- Composite
Where 27,015 fits
Why 27,015 is special
Counter-Strike, Team Fortress and Half-Life servers all use it, which makes 27015 the port a large number of people first forwarded through a home router. It sits alongside Minecraft's 25565 as accidental networking education.
27,015 is part of
Factors & digit properties
- Divisors (8)
- 1, 3, 5, 15, 1801, 5403, 9005, 27015
- Prime factorisation
- 3 × 5 × 1801
- Digit sum
- 15
- Digital root
- 6
Representations
- Decimal
- 27015
- Scientific notation
- 2.702 × 10^4
Roman numerals
Roman numerals as modelled here goes up to 3,999.
Binary
1 1 0 1 0 0 1 1 0 0 0 0 1 1 1
1 × 16,384 + 1 × 8,192 + 0 × 4,096 + 1 × 2,048 + 0 × 1,024 + 0 × 512 + 1 × 256 + 1 × 128 + 0 × 64 + 0 × 32 + 0 × 16 + 0 × 8 + 1 × 4 + 1 × 2 + 1 × 1 = 27,015
Octal
6 4 6 0 7
6 × 4,096 + 4 × 512 + 6 × 64 + 0 × 8 + 7 × 1 = 27,015
Hexadecimal
6 9 8 7
6 × 4,096 + 9 × 256 + 8 × 16 + 7 × 1 = 27,015
Read as powers of two: 16,384 + 8,192 + 2,048 + 256 + 128 + 4 + 2 + 1 = 27,015.
In historical numeral systems
Egyptian
2 fingers, 7 lotuses, 1 hobble, 5 strokes
2 × 10,000 + 7 × 1,000 + 1 × 10 + 5 × 1 = 27,015. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
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
- Happy number
- Harshad (Niven) number
Related numbers & connections
Two game server defaults that between them taught a generation about port forwarding and NAT, which no networking course managed at the same scale.
View 25565 →Numbers Around Us
- appears alongside25565
why?
Strength 0.50, confidence "high".
Technology & computing
Source engine servers — Counter-Strike, Team Fortress, Half-Life — default to 27015, making it one of the two ports a generation first forwarded through a home router. Minecraft's 25565 is the other, and between them they taught more people about NAT than any course did.
DocumentedTechnology & computing
Common questions
Is 27,015 a prime number?
No, 27,015 is not prime.
What are the factors of 27,015?
The factors of 27,015 are 1, 3, 5, 15, 1801, 5403, 9005, 27015.
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