125 (number)

125 is the natural number following 124 and preceding 126.

Mathematics

One hundred [and] twenty five is the cube of 5. It can be expressed as a sum of two squares in two different ways, 125 = 10² + 5² = 11² + 2².

125 and 126 form a Ruth-Aaron pair under the second definition in which repeated prime factors are counted as often as they occur.

Like so many other powers of 5, it is a Friedman number in base 10 since 125 = 5^{1 + 2}.

Music

Opus 125 is the ninth symphony of Ludwig van Beethoven, the longest symphony to the time of its completion, the first symphony to use a chorus, and Beethoven's last complete symphony.

Other fields

One hundred [and] twenty five or one two five may also refer to:

• The year AD 125 or 125 BC
• Unbipentium, the element with atomic number 125, which has not yet been discovered.
• The InterCity 125, sometimes referred to simply as "one two five"; a British high speed train

References

• Wells, D. The Penguin Dictionary of Curious and Interesting Numbers London: Penguin Group. (1987): 136