Skip to main content
Dictionary
Store
Blog
World
Help
Advertise
Chat
System Status
Information Collection Notice
Trademark Concerns
reCAPTCHA Privacy
Terms of Service
reCAPTCHA Terms
Privacy Policy
Accessibility
Report a Bug
Data Request
Contact Us
Security
DMCA
© 1999–2026 Urban Dictionary ®
Mugs
Tees
Hoodies
Pro Customization
Create unique products with your own words and definitions
Preview
Personalize Your Design
Your Word
Your Definition
138 is a sphenic number, the sum of four consecutive primes (29 + 31 + 37 + 41), and the smallest product of three primes, such that in base 10, the third prime is a concatenation of the other two: 2 ⋅ 3 ⋅ 23 . 138 is the third 47-gonal number and an Ulam number, as well as a one step palindrome (138 + 831 = 969.) 138 is the 72nd normal congruent number and the 49th primitive or square free congruent number.
Text fits
Save
Cancel