We are tasked with finding the remainder when \( \left( (64)^{64} \right)^{64} \) is divided by 7.
We begin by reducing \( 64 \mod 7 \). Since \( 64 \div 7 = 9 \) with a remainder of 1, we have:
\[
64 \equiv 1 \mod 7
\]
This means that \( 64^{64} \equiv 1^{64} \equiv 1 \mod 7 \), and similarly:
\[
(64^{64})^{64} \equiv 1^{64} \equiv 1 \mod 7
\]
Thus, the remainder when \( \left( (64)^{64} \right)^{64} \) is divided by 7 is \( 1 \).