All others are divisible by 13.
In all other options, digit at the second place is the difference from first and third digits.
Except '87', all a prime numbers 87 is divisible by 3.
Except '64', none of the numbers is a square or a cube.
Only 75 is divisible by 15.
All others are divisible by 7.
Except '841', all are even numbers.
In all other options, sum of the digits is 20.
3216 ? 3 + 2 + 6 - 1 = 10;
2338 ? 2 + 3 + 8 - 3 = 10;
3205 ? 3 + 2 + 5 - 0 = 10;
2015 ? 2 + 0 + 5 - 1 = 6
Therefore, 2015is different from the other three.
In all other options, digit in the middle is the sum of the other two digits.
All others are complete squares.
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