Eulers identity, 
  
    
      
        
          e
          
            i
            π
          
        
      
    
    {\displaystyle e^{i\pi }}
  + 
  
    
      
        1
      
    
    {\displaystyle 1}
   = 
  
    
      
        0
      
    
    {\displaystyle 0}
  , contains five essential numbers used widely in mathematics: Archimedes constant 
  
    
      
        π
      
    
    {\displaystyle \pi }
  , Eulers number 
  
    
      
        e
      
    
    {\displaystyle e}
  , the imaginary number 
  
    
      
        i
      
    
    {\displaystyle i}
  , unity 
  
    
      
        1
      
    
    {\displaystyle 1}
  , and zero 
  
    
      
        0
      
    
    {\displaystyle 0}
  , which makes this formula a renown example of beauty in mathematics.
There are only four known double Mersenne prime numbers, with a fifth candidate double Mersenne prime 
  
    
      
        
          M
          
            
              M
              
                61
              
            
          
        
      
    
    {\displaystyle M_{M_{61}}}
   =  223058...93951 − 1 too large to compute with current computers.