+**138** is a [natural number](/wiki/Natural_Number) nestled between 137 and 139. It is an [even number](/wiki/Even_Number) and a sphenic number, formed by the product of three distinct primes. This makes it a fascinating subject in number theory.
+## See also
+- [Sphenic Number](/wiki/Sphenic_Number)
+- [Abundant Number](/wiki/Abundant_Number)
+- [Number Theory](/wiki/Number_Theory)
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