Tinkering with an Armstrong number finding program function

$./app 
Sign detection [1] 
Power of two [2] 
Counting No. of bits set [3] 
Set or clear bits without branching[4] 
Find maximum value[5] 
Finding least common multiple[6] 
Finding the greatest commom divisor[7] 
Finding if a number is an Armstrong number or not[8] 
8
Enter a positive integer: 153
153 is an Armstrong number 
$./app 
Sign detection [1] 
Power of two [2] 
Counting No. of bits set [3] 
Set or clear bits without branching[4] 
Find maximum value[5] 
Finding least common multiple[6] 
Finding the greatest commom divisor[7] 
Finding if a number is an Armstrong number or not[8] 
8
Enter a positive integer: 154
154 is not an Armstrong number 
$./app 
Sign detection [1] 
Power of two [2] 
Counting No. of bits set [3] 
Set or clear bits without branching[4] 
Find maximum value[5] 
Finding least common multiple[6] 
Finding the greatest commom divisor[7] 
Finding if a number is an Armstrong number or not[8] 
8
Enter a positive integer: 1
1 is an Armstrong number 
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