Check whetherr 2 ^ ( p - 1 ) is prime or not .
p = 7 NEW_LINE checkNumber = 2 ** p - 1 NEW_LINE if isPrime ( p ) : NEW_LINE INDENT print ( checkNumber , ' is ▁ Prime . ' ) NEW_LINE DEDENT else : NEW_LINE INDENT print ( checkNumber , ' is ▁ not ▁ Prime ' ) NEW_LINE DEDENT