650
A standard CD holds about 650 megabytes.
- Even
- Composite
Where 650 fits
Why 650 is special
The capacity is often said to have been chosen so that Beethoven's Ninth Symphony would fit on one disc. The story is repeated by Sony itself and disputed in its details, and the more prosaic explanation is that 650 MB is what a 74-minute audio disc holds once encoded.
Same number, different meanings
How 650 is understood across different contexts — never implying one meaning because of another.
- Mathematics
The capacity is often said to have been chosen so that Beethoven's Ninth Symphony would fit on one disc. The story is repeated by Sony itself and disputed in its details, and the more prosaic explanation is that 650 MB is what a 74-minute audio disc holds once encoded.
- Technology & computing
The IBM 650, delivered from 1954, sold around two thousand units at a time when computers were expected to sell in tens. It was widely installed in universities and became a common teaching machine.
- Science
There are roughly 650 named skeletal muscles in the human body (adults; counts differ by how muscles are subdivided).
Factors & digit properties
- Divisors (12)
- 1, 2, 5, 10, 13, 25, 26, 50, 65, 130, 325, 650
- Prime factorisation
- 2 × 5^2 × 13
- Digit sum
- 11
- Digital root
- 2
Representations
- Decimal
- 650
- Scientific notation
- 6.500 × 10^2
Roman numerals
D C L
Binary
1 0 1 0 0 0 1 0 1 0
1 × 512 + 0 × 256 + 1 × 128 + 0 × 64 + 0 × 32 + 0 × 16 + 1 × 8 + 0 × 4 + 1 × 2 + 0 × 1 = 650
Octal
1 2 1 2
1 × 512 + 2 × 64 + 1 × 8 + 2 × 1 = 650
Hexadecimal
2 8 a
2 × 256 + 8 × 16 + a × 1 = 650
Read as powers of two: 512 + 128 + 8 + 2 = 650.
In historical numeral systems
Egyptian
6 coils of rope, 5 hobbles
6 × 100 + 5 × 10 = 650. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
1 corner wedge (sixties place), 5 corner wedges (units place)
10 × 60 + 50 = 650. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
chi, then nu, marked as a numeral
chi-nu + keraia
chi + nu 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 resh, then nun
tav-resh-nun
tav (400) + resh (200) + nun (50) = 650, 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
Related numbers & connections
CD and CD-R capacities. The extra 50 MB came from packing the spiral track slightly tighter within tolerances the drives already met.
View 700 →The 650 sold in thousands and the 704 introduced floating-point hardware; between them they made computing routine and capable.
View 704 →Technology & computing
The IBM 650, delivered from 1954, sold around two thousand units at a time when computers were expected to sell in tens. It was widely installed in universities and became a common teaching machine.
DocumentedTechnology & computingGeography: United StatesPeriod: 1954–1962A CD's roughly 650 MB is widely said to have been set so Beethoven's Ninth would fit. Sony executives have repeated the account and its details do not survive scrutiny; the technical figure is simply what a 74-minute audio disc holds once encoded.
DocumentedTechnology & computing
Science
There are roughly 650 named skeletal muscles in the human body (adults; counts differ by how muscles are subdivided).
DocumentedScienceGeography: adults; counts differ by how muscles are subdivided
Common questions
Is 650 a prime number?
No, 650 is not prime.
What are the factors of 650?
The factors of 650 are 1, 2, 5, 10, 13, 25, 26, 50, 65, 130, 325, 650.
What is 650 in Roman numerals?
650 in Roman numerals is DCL.
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: 15 July 2026