It can be simple if you know who is Fermat

The first step is to get the prime factors of this number:

$2744 \div 2 = 1372$

$1372 \div 2 = 686$

$686 \div 2 = 343$

$343 \div 7 = 49$

$49 \div 7 = 7$

$7\div 7 = 1$

Then, $2744=2^3 \cdot 7^3$ , which means that it's a perfect cube.

By Fermat's Last Theorem, there is no perfect cube that can be expressed by the sum of other perfect cubes. In general:

$a^x + b^x = c^x$ have no positive integer solution, when $x>2$ .