128 (number)

From Wikipedia, the free encyclopedia
← 127 128 129 →
← 120 121 122 123 124 125 126 127 128 129 →
List of numbers — Integers
← 0 100 200 300 400 500 600 700 800 900 →
Cardinalone hundred twenty-eight
Ordinal128th
(one hundred twenty-eighth)
Factorization27
Divisors1, 2, 4, 8, 16, 32, 64, 128
Greek numeralΡΚΗ´
Roman numeralCXXVIII
Binary100000002
Ternary112023
Octal2008
DuodecimalA812
Hexadecimal8016

128 (one hundred [and] twenty-eight) is the natural number following 127 and preceding 129.

In mathematics[]

128 is the seventh power of 2. It is the largest number which cannot be expressed as the sum of any number of distinct squares.[1][2] But it is divisible by the total number of its divisors, making it a refactorable number.[3]

The sum of Euler's totient function φ(x) over the first twenty integers is 128.[4]

128 can be expressed by a combination of its digits with mathematical operators thus 128 = 28 - 1, making it a Friedman number in base 10.[5]

A hepteract has 128 vertices.

128 is the only 3-digit number that is a 7th power (27).

In bar codes[]

  • Code 128 is a Uniform Symbology Specification (USS Code 128) alphanumeric bar code that encodes text, numbers, numerous functions, and designed to encode all 128 ASCII characters (ASCII 0 to ASCII 127), as used in the shipping industry.
  • Subdivisions include:
    • 128A (0-9, A-Z, ASCII control codes, special characters)
    • 128B (0-9, A-Z, a-z, special characters)
    • 128C (00-99 numeric characters)
    • GS1-128 application standard of the GS1 implementation using the Code 128 barcode specification
    • ISBT 128 system for blood product labeling for the International Society of Blood Transfusion

In computing[]

  • 128-bit key size encryption for secure communications over the Internet
    • IPv6 uses 128-bit (16-byte) addresses
    • Any bit with a binary prefix is 128 bytes of a lesser binary prefix value, such as 1 gibibit is 128 mebibytes
    • 128-bit integers, memory addresses, or other data units are those that are at most 128 bits 16 octets wide
  • ASCII includes definitions for 128 characters (33 non-printing characters, mostly obsolete control characters that affect how text is processed, and 94 printable)
  • A 128-bit integer can represent up to 3.40282366...e+38 values (2128 = 340,282,366,920,938,463,463,374,607,431,768,211,456).
  • CAST-128 is a block cipher used in a number of products, notably as the default cipher in some versions of GPG and PGP.
  • Graphics cards have a 128-bit, 256-bit, or 512-bit data bus to memory.
  • Atari 2600 consoles have 128 bytes of memory
  • Sony's PlayStation 2 Emotion Engine CPU has two 128-bit vector units
  • Macintosh 128K was the original Apple Macintosh personal computer released in 1984
  • Laser 128 released by VTech was a clone of the Apple II released in 1984
  • Commodore 128 home/personal computer which had a 128 KB of memory released in 1985
  • Enterprise 128 Zilog Z80 home computer released in 1985
  • Jane 128 was a GUI-based integrated software package for the Commodore 128 personal computer released in 1985
  • RIVA 128 (Real-time Interactive Video and Animation accelerator) was one of the first consumer graphics chips to integrate 3D and video acceleration in 1997
  • Super Mario 128 is a cancelled Nintendo game, though many elements were included in Super Mario Galaxy and Pikmin

In the military[]

  • USNS Mission San Luis Rey (T-AO-128) was a United States Navy Mission Buenaventura-class fleet oilers during World War II
  • USS Arenac (APA-128) was a United States Navy Haskell-class attack transport during World War II
  • USS Cavallaro (APD-128) was a United States Navy Crosley-class high speed transport
  • USS Leonis (AK-128) was a United States Navy Crater-class cargo ship during World War II
  • USS Velocity (AM-128) was a United States Navy Auk-class minesweeper which removed naval mines laid in the water

In transportation[]

  • A small car manufactured by Fiat, the Fiat 128 from 1969 to 1985. SEAT 128 was a 2-door coupé version of the car
  • The BMW 128i convertible
  • 128 is the number of many roads, including Massachusetts Route 128, Boston's inner beltway.
  • Route 128 Station is a stop on the Massachusetts Bay Transportation Authority Attleboro/Providence MBTA Commuter Rail line in Westwood, Massachusetts
  • STS-128 was a Space Shuttle Discovery mission to the International Space Station in 2009

In other fields[]

One hundred [and] twenty-eight is also:

  • The year AD 128 or 128 BC
  • 128 AH is a year in the Islamic calendar that corresponds to 745 – 746 CE
  • 128 Nemesis is a main belt asteroid
  • Ross 128 is a red dwarf star, eleventh closest star system to the Solar System
  • 128P/Shoemaker-Holt is a periodic comet in the Solar system
  • The atomic number of unbioctium, an element yet to be discovered
  • The number of musical instruments specified in General MIDI. Sometimes they are numbered 0 to 127 and sometimes they are numbered 1 to 128.
  • 128 film, a film format
  • Sonnet 128 by William Shakespeare
  • In music, a hundred twenty-eighth note is a note played for 1/128 of the duration of a whole note
  • The number of US fluid ounces in a US gallon

See also[]

Notes[]

  1. ^ Sprague, R. (1948), "Über Zerlegungen in ungleiche Quadratzahlen", Math. Z., 51 (3): 289–290, doi:10.1007/BF01181594, MR 0027285, S2CID 123515191
  2. ^ OEIS:A001422. Similarly, the largest numbers that cannot be expressed as sums of distinct cubes and fourth powers, respectively, are 12758 and 5134240 (sequence A001661 in the OEIS).
  3. ^ OEIS:A033950.
  4. ^ OEIS:A002088.
  5. ^ OEIS:A036057.

References[]

  • Wells, D. The Penguin Dictionary of Curious and Interesting Numbers London: Penguin Group. (1987): 138

External links[]

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