155 is an odd composite number composed of two prime numbers multiplied together.

What does the number 155 look like?

This visualization shows the relationship between its 2 prime factors (large circles) and 4 divisors.

155 is an odd composite number. It is composed of two distinct prime numbers multiplied together. It has a total of four divisors.

Prime factorization of 155:

5 × 31

See below for interesting mathematical facts about the number 155 from the Numbermatics database.

Names of 155

  • Cardinal: 155 can be written as One hundred fifty-five.

Scientific notation

  • Scientific notation: 1.55 × 102

Factors of 155

  • Number of distinct prime factors ω(n): 2
  • Total number of prime factors Ω(n): 2
  • Sum of prime factors: 36

Divisors of 155

  • Number of divisors d(n): 4
  • Complete list of divisors:
    1 5 31 155
  • Sum of all divisors σ(n): 192
  • Sum of proper divisors (its aliquot sum) s(n): 37
  • 155 is a deficient number, because the sum of its proper divisors (37) is less than itself. Its deficiency is 118

Bases of 155

  • Binary: 100110112
  • Hexadecimal: 0x9B
  • Base-36: 4B

Squares and roots of 155

  • 155 squared (1552) is 24025
  • 155 cubed (1553) is 3723875
  • The square root of 155 is 12.4498995979
  • The cube root of 155 is 5.3716853549

Scales and comparisons

How big is 155?
  • 155 seconds is equal to 2 minutes, 35 seconds.
  • To count from 1 to 155 would take you about seventeen seconds.

    This is a very rough estimate, based on a speaking rate of half a second every third order of magnitude. If you speak quickly, you could probably say any randomly-chosen number between one and a thousand in around half a second. Very big numbers obviously take longer to say, so we add half a second for every extra x1000. (We do not count involuntary pauses, bathroom breaks or the necessity of sleep in our calculation!)

  • A cube with a volume of 155 cubic inches would be around 0.4 feet tall.

Recreational maths with 155

  • 155 backwards is 551
  • The number of decimal digits it has is: 3
  • The sum of 155's digits is 11
  • More coming soon!

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"Number 155 - Facts about the integer". Numbermatics.com. 2023. Web. 30 March 2023.

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Numbermatics. 2023. "Number 155 - Facts about the integer". https://numbermatics.com/n/155/

The information we have on file for 155 includes mathematical data and numerical statistics calculated using standard algorithms and methods. We are adding more all the time. If there are any features you would like to see, please contact us. Information provided for educational use, intellectual curiosity and fun!

Keywords: Divisors of 155, math, Factors of 155, curriculum, school, college, exams, university, Prime factorization of 155, STEM, science, technology, engineering, physics, economics, calculator, one hundred fifty-five.

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