515
Port 515 carries the Line Printer Daemon protocol.
- Odd
- Composite
Where 515 fits
Why 515 is special
LPD dates from Berkeley Unix and is still spoken by office printers decades after better protocols arrived. Its persistence is the ordinary reason obsolete protocols survive: the devices work, replacing them costs money, and nobody is harmed until someone scans the network.
515 is part of
Factors & digit properties
- Divisors (4)
- 1, 5, 103, 515
- Prime factorisation
- 5 × 103
- Digit sum
- 11
- Digital root
- 2
Representations
- Decimal
- 515
- Binary
- 1000000011
- Octal
- 1003
- Hexadecimal
- 203
- Roman numeral
- DXV
- Scientific notation
- 5.150 × 10^2
Other mathematical patterns
- Palindromic number
- Deficient number
- Semiprime
Related numbers & connections
LPD dates from Berkeley Unix and IPP replaced it. Printers still answer on both, which is why printer fleets are a standing security finding.
View 631 →Other connections
- is associated with631
why?
Strength 0.50, confidence "high".
Technology & computing
LPD predates the web and remains enabled on a large share of network printers. Legacy protocols persist not because they are good but because the hardware speaking them still functions, which is why printer fleets are a standing security finding.
DocumentedTechnology & computing
Common questions
Is 515 a prime number?
No, 515 is not prime.
What are the factors of 515?
The factors of 515 are 1, 5, 103, 515.
What is 515 in Roman numerals?
515 in Roman numerals is DXV.
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: 3 August 2026