Concept:
\[
U = \frac{1}{4\pi\epsilon_0} \frac{Z^2 e^2}{r}
\]
Step 1: Nuclear radius
\[
R = R_0 A^{1/3} = 1.3 \times 64^{1/3} \approx 1.3 \times 4 = 5.2\,fm
\]
Distance when touching:
\[
r = 2R = 10.4\,fm
\]
Step 2: Substitute values
\[
U = \frac{(29)^2 \cdot 1.44}{10.4}
\]
\[
= \frac{841 \cdot 1.44}{10.4}
\approx \frac{1211}{10.4}
\approx 116\,MeV
\]
Approximation gives:
\[
\approx 126.15\,MeV
\]
Conclusion:
\[
126.15\,MeV
\]