500
500 is the distance in miles of the Indianapolis 500, one of motorsport's oldest and most prestigious races, run annually since 1911.
- Even
- Composite
Where 500 fits
Why 500 is special
500 miles is the exact length of the Indianapolis 500 — 200 laps of the 2.5-mile Indianapolis Motor Speedway oval — run every year since 1911 (aside from wartime pauses) and regarded as one of the 'Triple Crown of Motorsport' races. In U.S. currency history, the $500 bill was also issued (last printed 1945) and remains legal tender, though it's no longer produced or normally circulated.
Same number, different meanings
How 500 is understood across different contexts — never implying one meaning because of another.
- Mathematics
500 miles is the exact length of the Indianapolis 500 — 200 laps of the 2.5-mile Indianapolis Motor Speedway oval — run every year since 1911 (aside from wartime pauses) and regarded as one of the 'Triple Crown of Motorsport' races. In U.S. currency history, the $500 bill was also issued (last printed 1945) and remains legal tender, though it's no longer produced or normally circulated.
- Everyday life
E500 covers sodium carbonates including bicarbonate of soda, used as a raising agent and acidity regulator. The same compound is sold domestically without any additive designation.
- Science
There are about 500 million neurons in the wall of the human gut (adults). More than in the spinal cord. The gut can run its own peristalsis with the brain disconnected entirely, which is why it is sometimes called a second brain.
- History
The United States printed $500 bills until 1945; production stopped in 1969 due to low public use, but existing notes remain legal tender.
- Technology & computing
500 is the HTTP status for an unhandled server error — the code returned when something broke and nothing more specific applies. Because it leaks no detail it is also the safe default: a stack trace in a 500 body is a well-known way to hand an attacker a map of the system.
- Geography
There are roughly 500 thousand earthquakes detected each year. About 100,000 of them are strong enough to be felt, and around 100 cause damage. The rest are known only to instruments.
- Finance & economics
The Fortune 500, the Indy 500 and the Daytona 500 all use the figure because it is round and memorable. Nothing about 500 recommends it beyond that, which is worth stating plainly.
- Sport
The Indianapolis 500 is a 500-mile (200-lap) motor race held annually at the Indianapolis Motor Speedway since 1911, one of the oldest and most prestigious races in the world and part of the informal 'Triple Crown of Motorsport'.
Not just a mathematical number
500is also used in ways where ordinary arithmetic doesn't apply — each listed below with what genuinely does and doesn't follow from it.
- Mathematical number
A genuine quantity — its mathematical properties (prime, square, factors, and so on) are real facts about it.
A genuine quantity that ordinary arithmetic applies to — it can be prime, even, a perfect square, added to another number meaningfully, and so on.
- Code
Also used as a code — HTTP status codes.
An assigned identifier from a fixed registry or standard — its digits don't represent an amount, and arithmetic on it is meaningless (HTTP status 404 + 1 is not a 'better' status; it's a different, unrelated code).
500 is part of
Factors & digit properties
- Divisors (12)
- 1, 2, 4, 5, 10, 20, 25, 50, 100, 125, 250, 500
- Prime factorisation
- 2^2 × 5^3
- Digit sum
- 5
- Digital root
- 5
Representations
- Decimal
- 500
- Scientific notation
- 5.000 × 10^2
Roman numerals
D
Binary
1 1 1 1 1 0 1 0 0
1 × 256 + 1 × 128 + 1 × 64 + 1 × 32 + 1 × 16 + 0 × 8 + 1 × 4 + 0 × 2 + 0 × 1 = 500
Octal
7 6 4
7 × 64 + 6 × 8 + 4 × 1 = 500
Hexadecimal
1 f 4
1 × 256 + f × 16 + 4 × 1 = 500
Read as powers of two: 256 + 128 + 64 + 32 + 16 + 4 = 500.
In historical numeral systems
Egyptian
5 coils of rope
5 × 100 = 500. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
8 vertical wedges (sixties place), 2 corner wedges (units place)
8 × 60 + 20 = 500. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
phi, marked as a numeral
phi + keraia
A single letter, phi, marked with a keraia to show it is a number rather than a word.
Hebrew numerals
tav, then qof
tav-qof
tav (400) + qof (100) = 500, written in descending order.
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
- Abundant number
- Powerful number
- Harshad (Niven) number
Related numbers & connections
500 is a multiple of 100 (100 × 5 = 500).
View 100 →The two server-side codes users actually meet. 500 means something broke unexpectedly; 503 means the server is deliberately declining, whether for maintenance or to shed load. One is a failure, the other a decision.
View 503 →The two ends of the outcome space: the request succeeded, or the server failed while handling it.
View 200 →Mathematically related
- is a multiple of100
why?
Strength 0.50, confidence "high".
Numbers Around Us
- appears alongside503
why?
Strength 0.50, confidence "high".
- appears inEarth
why?
Strength 0.50, confidence "high".
- appears inNumbers assigned as identifiers
why?
Strength 0.50, confidence "high".
- appears inHTTP status codes
why?
Strength 0.50, confidence "high".
- appears inSignature motor-race distance
why?
Strength 0.50, confidence "high".
Everyday life
E500 covers sodium carbonates including bicarbonate of soda, used as a raising agent and acidity regulator. The same compound is sold domestically without any additive designation.
DocumentedEveryday lifeGeography: European Union and states adopting the E number systemPeriod: 1962–There are 500 sheets in a ream of paper (worldwide, modern usage). It was 480 for centuries — twenty quires of 24 — and moved to 500 as machine production made the older count pointless. The 480-sheet ream survives as the 'short ream' in some trades.
DocumentedEveryday lifeGeography: worldwide, modern usageThere are about 500 million tonnes of rice harvested worldwide each year (worldwide, milled rice). Figure as of 2023. Around 90 per cent of it is grown and eaten in Asia.
DocumentedEveryday lifeGeography: worldwide, milled rice
Science
There are about 500 million neurons in the wall of the human gut (adults). More than in the spinal cord. The gut can run its own peristalsis with the brain disconnected entirely, which is why it is sometimes called a second brain.
DocumentedScienceGeography: adultsThere are about 500 million alveoli in a pair of adult human lungs (adults). Their combined surface area is roughly that of a tennis court, folded into a chest cavity.
DocumentedScienceGeography: adults
History
The United States printed $500 bills until 1945; production stopped in 1969 due to low public use, but existing notes remain legal tender.
DocumentedHistoryGeography: United StatesPeriod: issued until 1945, discontinued 1969
Technology & computing
500 is the HTTP status for an unhandled server error — the code returned when something broke and nothing more specific applies. Because it leaks no detail it is also the safe default: a stack trace in a 500 body is a well-known way to hand an attacker a map of the system.
DocumentedTechnology & computing
Geography
There are roughly 500 thousand earthquakes detected each year. About 100,000 of them are strong enough to be felt, and around 100 cause damage. The rest are known only to instruments.
DocumentedGeographyGeography: worldwideThere are about 500 thousand cubic kilometres of water falling as precipitation each year. About four-fifths of it onto the ocean. The same water evaporates again, so the figure is a rate of circulation rather than a quantity of anything.
DocumentedGeographyGeography: worldwide
Finance & economics
The Fortune 500, the Indy 500 and the Daytona 500 all use the figure because it is round and memorable. Nothing about 500 recommends it beyond that, which is worth stating plainly.
DocumentedFinance & economics
Sport
The Indianapolis 500 is a 500-mile (200-lap) motor race held annually at the Indianapolis Motor Speedway since 1911, one of the oldest and most prestigious races in the world and part of the informal 'Triple Crown of Motorsport'.
DocumentedSportGeography: United StatesPeriod: annually since 1911
Common questions
Is 500 a prime number?
No, 500 is not prime.
What are the factors of 500?
The factors of 500 are 1, 2, 4, 5, 10, 20, 25, 50, 100, 125, 250, 500.
What is 500 in Roman numerals?
500 in Roman numerals is D.
About this page's data
Mathematical facts:computed directly from the number's value — nothing to source or verify externally.
Contextual records: 11 reviewer-confirmed records, sourced and reviewed before publication.
Last reviewed: 15 July 2026