70976
After 1 and 9 , 225 is the third smallest number " n " for which , where " & sigma ; " is the sum of divisors function and " & phi ; " is Euler 's totient function .
 Euler
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Euler