103
103 is the ambulance number across much of the former Soviet Union.
- Odd
- Prime
Where 103 fits
Why 103 is special
103 completes a numbering scheme designed in the Soviet era and still in use: 101 fire, 102 police, 103 ambulance, 104 gas leak. The gas-leak line is the unusual one — few countries treat a domestic gas emergency as a separate three-digit service, and its presence reflects how widely piped gas was distributed.
Same number, different meanings
How 103 is understood across different contexts — never implying one meaning because of another.
- Mathematics
103 completes a numbering scheme designed in the Soviet era and still in use: 101 fire, 102 police, 103 ambulance, 104 gas leak. The gas-leak line is the unusual one — few countries treat a domestic gas emergency as a separate three-digit service, and its presence reflects how widely piped gas was distributed.
- History
The 101/102/103/104 assignment — fire, police, ambulance, gas leak — dates from Soviet telephony and survives across the successor states. The separate gas-leak line is the distinctive part: few countries give a domestic gas emergency its own three-digit number, and its presence reflects how comprehensively piped gas was installed.
- Science
Lawrencium honours Ernest Lawrence, who built the cyclotron. Every synthetic element depends on accelerators, so the name credits the machine that made the whole class possible.
103 is part of
Factors & digit properties
- Divisors (2)
- 1, 103
- Prime factorisation
- 103
- Digit sum
- 4
- Digital root
- 4
Representations
- Decimal
- 103
- Binary
- 1100111
- Octal
- 147
- Hexadecimal
- 67
- Roman numeral
- CIII
- Scientific notation
- 1.030 × 10^2
Other mathematical patterns
- Deficient number
- Happy number
- Twin prime
Related numbers & connections
Two thirds of a single Soviet-era scheme still in use across the successor states: 101 fire, 102 police, 103 ambulance, 104 gas leak. The numbers are learned as a set, and the separate gas line is what distinguishes the scheme from most others.
View 102 →Numbers Around Us
- appears alongside102
why?
Strength 0.50, confidence "high".
History
The 101/102/103/104 assignment — fire, police, ambulance, gas leak — dates from Soviet telephony and survives across the successor states. The separate gas-leak line is the distinctive part: few countries give a domestic gas emergency its own three-digit number, and its presence reflects how comprehensively piped gas was installed.
DocumentedHistoryGeography: Russia, Ukraine, Kazakhstan and other CIS states
Science
Lawrencium honours Ernest Lawrence, who built the cyclotron. Every synthetic element depends on accelerators, so the name credits the machine that made the whole class possible.
DocumentedScienceComet 103P/Hartley 2 was visited by the EPOXI mission in 2010. Its carbon dioxide-driven jets produced activity disproportionate to its size, with icy chunks visible around the nucleus.
DocumentedSciencePeriod: 1986–
Common questions
Is 103 a prime number?
Yes, 103 is prime — it has exactly two positive divisors: 1 and itself.
What are the factors of 103?
The factors of 103 are 1, 103.
What is 103 in Roman numerals?
103 in Roman numerals is CIII.
About this page's data
Mathematical facts:computed directly from the number's value — nothing to source or verify externally.
Contextual records: 3 reviewer-confirmed records, sourced and reviewed before publication.
Last reviewed: 3 August 2026