480
480 lines is standard-definition video, and 480 Mbit/s is USB 2.0's speed.
- Even
- Composite
Where 480 fits
Why 480 is special
The two are unrelated and both were the baseline of their era. NTSC's 480 visible lines governed television for half a century, and USB 2.0's 480 Mbit/s made external hard drives practical.
Same number, different meanings
How 480 is understood across different contexts — never implying one meaning because of another.
- Mathematics
The two are unrelated and both were the baseline of their era. NTSC's 480 visible lines governed television for half a century, and USB 2.0's 480 Mbit/s made external hard drives practical.
- History
Thermopylae delayed the Persian advance and Salamis ended the invasion by destroying the fleet that supplied it. The defeat is far better remembered than the victory.
- Technology & computing
480 describes both the visible lines of standard-definition television and the megabits per second of USB 2.0. Neither derives from the other; both happened to define the ordinary case for their period.
Factors & digit properties
- Divisors (24)
- 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 48, 60, 80, 96, 120, 160, 240, 480
- Prime factorisation
- 2^5 × 3 × 5
- Digit sum
- 12
- Digital root
- 3
Representations
- Decimal
- 480
- Scientific notation
- 4.800 × 10^2
Roman numerals
C D L X X X
CDLXXX uses the subtractive pair CD: a hundred before five hundred — five hundred minus a hundred.
Binary
1 1 1 1 0 0 0 0 0
1 × 256 + 1 × 128 + 1 × 64 + 1 × 32 + 0 × 16 + 0 × 8 + 0 × 4 + 0 × 2 + 0 × 1 = 480
Octal
7 4 0
7 × 64 + 4 × 8 + 0 × 1 = 480
Hexadecimal
1 e 0
1 × 256 + e × 16 + 0 × 1 = 480
Read as powers of two: 256 + 128 + 64 + 32 = 480.
In historical numeral systems
Egyptian
4 coils of rope, 8 hobbles
4 × 100 + 8 × 10 = 480. 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), empty units place
8 × 60 + 0 = 480. Places are separated by a space on the tablet, with the higher place written first. The second place is empty, and this is precisely the case the early system could not write unambiguously — the same wedges alone would also read as 1.
Greek (Ionic)
upsilon, then pi, marked as a numeral
upsilon-pi + keraia
upsilon + pi written in descending order and added — the letters carry their values wherever they stand, so this is addition, not place value.
Hebrew numerals
tav, then pe
tav-pe
tav (400) + pe (80) = 480, 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
- Harshad (Niven) number
Related numbers & connections
Marathon in 490 BC and Thermopylae and Salamis ten years later are the two Persian invasions of Greece. The first was repelled by Athens alone and the second required a Greek coalition.
View 490 →Thermopylae in 480 BC is remembered as 300 Spartans, and about 7,000 Greeks held the pass. The figure is accurate about one contingent and misleading about the battle.
View 300 →History
Thermopylae delayed the Persian advance and Salamis ended the invasion by destroying the fleet that supplied it. The defeat is far better remembered than the victory.
DocumentedHistoryGeography: GreecePeriod: 480 BC
Technology & computing
480 describes both the visible lines of standard-definition television and the megabits per second of USB 2.0. Neither derives from the other; both happened to define the ordinary case for their period.
DocumentedTechnology & computing
Common questions
Is 480 a prime number?
No, 480 is not prime.
What are the factors of 480?
The factors of 480 are 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 48, 60, 80, 96, 120, 160, 240, 480.
What is 480 in Roman numerals?
480 in Roman numerals is CDLXXX. CD is subtractive: a hundred before five hundred — five hundred minus a hundred. Written additively it would be CCCCLXXX, which Roman inscriptions used freely — the strict subtractive form is a later convention.
About this page's data
Mathematical facts:computed directly from the number's value — nothing to source or verify externally.
Contextual records: 2 reviewer-confirmed records, sourced and reviewed before publication.
Last reviewed: 15 July 2026