Prime number function

gistfile1.txt

  def is_prime_number? number
    index = 2                    
    tmp = 0                      
    while index <= number        
      if tmp < 1                 
        if (number % index) == 0 
          tmp += 1               
        end                      
      else                       
        return false             
      end                        
      index += 1                 
    end                          
    return true                   
  end

puts "Give me a number"

number_to_compare = gets


if is_prime_number? number_to_compare.to_i 
  puts "Is a prime number"
else
  puts "Is not a prime number"
end


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result in console:

Give me a number
137
Is a prime number