105
105 is the police emergency number in Peru.
- Odd
- Composite
Where 105 fits
Why 105 is special
105 is a reminder that emergency numbering is national, not natural. Peru routes police to 105 while its neighbours use 911, 133 or 123, so a traveller crossing a land border in South America changes emergency number as often as currency. Peru also runs 116 for fire and 106 for ambulance.
105 connects to:
- emergency telephone numbers — is used by
- 110 — contrasts with
Same number, different meanings
How 105 is understood across different contexts — never implying one meaning because of another.
- Mathematics
105 is a reminder that emergency numbering is national, not natural. Peru routes police to 105 while its neighbours use 911, 133 or 123, so a traveller crossing a land border in South America changes emergency number as often as currency. Peru also runs 116 for fire and 106 for ambulance.
- Science
The 1997 resolution distributed element names between the competing laboratories. Dubnium, berkelium and californium mean the periodic table records a Cold War scientific rivalry and its negotiated end.
- Geography
Peru reaches police on 105 while several neighbouring countries use different digits entirely. Regional blocs have generally added a shared number alongside national ones rather than replacing them, which is the same pattern the European Union followed.
- Finance & economics
There are about 105 trillion US dollars of world economic output each year (worldwide, at market exchange rates). Figure as of 2023. Measured instead by purchasing power the figure is nearer 165 trillion, and the ranking of economies changes with it. Neither is more correct; they answer different questions.
105 is part of
Factors & digit properties
- Divisors (8)
- 1, 3, 5, 7, 15, 21, 35, 105
- Prime factorisation
- 3 × 5 × 7
- Digit sum
- 6
- Digital root
- 6
Representations
- Decimal
- 105
- Scientific notation
- 1.050 × 10^2
Roman numerals
C V
Binary
1 1 0 1 0 0 1
1 × 64 + 1 × 32 + 0 × 16 + 1 × 8 + 0 × 4 + 0 × 2 + 1 × 1 = 105
Octal
1 5 1
1 × 64 + 5 × 8 + 1 × 1 = 105
Hexadecimal
6 9
6 × 16 + 9 × 1 = 105
Read as powers of two: 64 + 32 + 8 + 1 = 105.
In historical numeral systems
Egyptian
1 coil of rope, 5 strokes
1 × 100 + 5 × 1 = 105. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
1 vertical wedge (sixties place), 4 corner wedges + 5 vertical wedges (units place)
1 × 60 + 45 = 105. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
rho, then epsilon, marked as a numeral
rho-epsilon + keraia
rho + epsilon written in descending order and added — the letters carry their values wherever they stand, so this is addition, not place value.
Hebrew numerals
qof, then he
qof-he
qof (100) + he (5) = 105, written in descending order.
Maya
1 bar (upper, twenties place) over 1 bar (lower, units place)
5 × 20 + 5 = 105. 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
- Triangular number
- Deficient number
- Lucky number (mathematical sieve)
Related numbers & connections
105 reaches police in Peru, one of many national assignments that never converged.
Two national police numbers that never converged, which is the normal situation rather than the exception.
View 110 →Numbers Around Us
- is used byEmergency telephone numbers
why?
Strength 0.50, confidence "high".
Other connections
- contrasts with110
why?
Strength 0.50, confidence "high".
Science
The 1997 resolution distributed element names between the competing laboratories. Dubnium, berkelium and californium mean the periodic table records a Cold War scientific rivalry and its negotiated end.
DocumentedScience
Geography
Peru reaches police on 105 while several neighbouring countries use different digits entirely. Regional blocs have generally added a shared number alongside national ones rather than replacing them, which is the same pattern the European Union followed.
DocumentedGeographyGeography: PeruPeriod: 20th century–Peru routes police to 105, fire to 116 and ambulance to 106. Its neighbours use different numbers again — 911 in some, 133 or 123 in others — so a traveller moving through South America changes emergency number about as often as currency. Nothing about the digits is inherent; each is an administrative choice.
DocumentedGeographyGeography: Peru
Finance & economics
There are about 105 trillion US dollars of world economic output each year (worldwide, at market exchange rates). Figure as of 2023. Measured instead by purchasing power the figure is nearer 165 trillion, and the ranking of economies changes with it. Neither is more correct; they answer different questions.
DocumentedFinance & economicsGeography: worldwide, at market exchange rates
Common questions
Is 105 a prime number?
No, 105 is not prime.
What are the factors of 105?
The factors of 105 are 1, 3, 5, 7, 15, 21, 35, 105.
What is 105 in Roman numerals?
105 in Roman numerals is CV.
About this page's data
Mathematical facts:computed directly from the number's value — nothing to source or verify externally.
Contextual records: 4 reviewer-confirmed records, sourced and reviewed before publication.
Last reviewed: 15 July 2026