In mathematics
135 is the natural number following 134 and preceding 136.
135 = 11 + 32 + 53. (175, 518, and 598 also have this property). 135 is a Harshad number.
In other fields
135 is the name of the 35mm film standard, the most popular film format in the world.
In astrology, when two planets are 135 degrees apart, they are in an astrological aspect called a sesquiquadrate. The aspect was first used by Johannes Kepler.
The year 135 AD or 135 BC.