smith number

A smith number is any number whose sum of individual digits is also equal to the sum of the digits of its prime factorisation.

Smith numbers were named by Albert Wilansky of Lehigh University for his brother-in-law Harold Smith, who noticed the property in his phone number.

22 is a smith number because:
2+2 = 4
22 = 2*11
2+1+1 = 4
hence, 22 is a smith number.

by anon123456789 August 11, 2005