155 (number)

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← 154 155 156 →
150 151 152 153 154 155 156 157 158 159
List of numbersIntegers
0 100 200 300 400 500 600 700 800 900
Cardinalone hundred fifty-five
Ordinal155th
(one hundred fifty-fifth)
Factorization5 × 31
Divisors1, 5, 31, 155
Greek numeralΡΝΕ´
Roman numeralCLV
Binary100110112
Ternary122023
Octal2338
Duodecimal10B12
Hexadecimal9B16

155 (one hundred [and] fifty-five) is the natural number following 154 and preceding 156.

In mathematics[]

155 is:

  • a composite number
  • a semiprime.
  • a deficient number, since 1+5+31=37<155.
  • odious, since its binary expansion has a total of 5 ones in it.

There are 155 primitive permutation groups of degree 81. OEISA000019

If one adds up all the primes from the least through the greatest prime factors of 155, that is, 5 and 31, the result is 155. (sequence A055233 in the OEIS) Only three other "small" semiprimes (10, 39, and 371) share this attribute.

In the military[]

In sports[]

  • The maximum possible score in a single break in snooker, with a free ball at the start of the break (147 is the highest possible without a free ball)

In transportation[]

In other fields[]

155 is also:

  • The year AD 155 or 155 BC
  • 155 is the number for the International Operator in the United Kingdom
  • 155 AH is a year in the Islamic calendar that corresponds to 771 – 772 CE
  • 155 Scylla is a main belt asteroid
  • Europium-155 is a radioisotope or Europium and fission product with a half-life of 4.76 years
  • , a 2007 song by the band +44
  • The dialing code for Obihiro, Japan
  • The atomic number of an element temporarily called unquintquinttium
  • 155 North Wacker is a 46-story skyscraper in Chicago
  • Wolseley No. 155, Saskatchewan is a rural municipality in Canada

See also[]

References[]

External links[]

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