138 is a sphenic number,[1] and the smallest product of three primes such that in base 10, the third prime is a concatenation of the other two: [math]\displaystyle{ 2 \cdot 3 \cdot 23 }[/math].[lower-alpha 1] It is also a one-step palindrome in decimal (138 + 831 = 969).
Four concentric magic circles, with a magic constant of 138.
The Saros number of the solar eclipse series which began on June 6, 1472, and will end on July 11, 2716. The duration of Saros series 138 is 1244 years, and it contains 70 solar eclipses
138 Tolosa is a brightly colored, stony main belt asteroid
The New General Catalogue object NGC 138, a spiral galaxy in the constellation Pisces
138P/Shoemaker-Levy is a periodic comet in the Solar System
In media
"We Are 138", a 1978 song by the American punk rock band Misfits.
Who's Afraid of 138!? is a trance record label operated by Dutch DJ Armin van Buuren, as a reference to the use of 138 BPM in some forms of trance music.[18][19]
See also
The year AD 138 or 138 BC
List of highways numbered 138
Notes
↑The only other number less than 1000 in decimal with this property is 777 = 3 × 7 × 37.
↑This magic sum is generated from points that simultaneously lie on circles and diagonals, and, importantly, without including 9 in this sum (i.e. by bypassing it).
↑Using a different set of rules than Miller's rules for stellating polyhedra. For example, by Miller's rules, the triakis tetrahedron produces a total of 188 stellations, 136 of which are chiral. Using this same set of (Miller) rules, its dual polyhedron, the truncated tetrahedron, produces only 9 stellations, without including the truncated tetrahedron.