Find all prime numbers such that the square of the prime number can be written as the sum of cubes of two positive integers.
To find all prime numbers \( p \) such that \( p^2 \) can be written as the sum of cubes of two positive integers, we start with the equation:

\[ p^2 = a^3 + b^3 \]

We can use the factorization of the sum of cubes:

\[ a^3 + b^3 = (a + b)(a^2 - ab + b^2) \]

Thus, we have:

\[ p^2 = (a + b)(a^2 - ab + b^2) \]

Since \( p \) is a prime number, the factors on the right-hand side must be such that one of them is \( p \) and the other is \( p \) as well, because \( p^2 \) is a product of two factors, both of which must be \( p \) if they are to multiply to \( p^2 \). Therefore, we have two cases to consider:

1. \( a + b = p \) and \( a^2 - ab + b^2 = p \)
2. \( a + b = 1 \) and \( a^2 - ab + b^2 = p^2 \)

We will first consider the case \( a + b = p \) and \( a^2 - ab + b^2 = p \).

From \( a + b = p \), we can substitute \( b = p - a \) into the second equation:

\[ a^2 - a(p - a) + (p - a)^2 = p \]

Simplifying this, we get:

\[ a^2 - ap + a^2 + p^2 - 2ap + a^2 = p \]
\[ 3a^2 - 3ap + p^2 = p \]
\[ 3a^2 - 3ap + p^2 - p = 0 \]

This is a quadratic equation in \( a \):

\[ 3a^2 - 3ap + (p^2 - p) = 0 \]

Using the quadratic formula \( a = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \), we get:

\[ a = \frac{3p \pm \sqrt{(3p)^2 - 4 \cdot 3 \cdot (p^2 - p)}}{2 \cdot 3} \]
\[ a = \frac{3p \pm \sqrt{9p^2 - 12p^2 + 12p}}{6} \]
\[ a = \frac{3p \pm \sqrt{-3p^2 + 12p}}{6} \]
\[ a = \frac{3p \pm \sqrt{3p(4 - p)}}{6} \]

For \( a \) to be an integer, the discriminant \( 3p(4 - p) \) must be a perfect square. Since \( p \) is a prime number, the only possible value for \( p \) that makes \( 3p(4 - p) \) a perfect square is \( p = 3 \).

Let's verify \( p = 3 \):

If \( p = 3 \), then:

\[ a + b = 3 \]
\[ a^2 - ab + b^2 = 3 \]

We can try \( a = 1 \) and \( b = 2 \):

\[ 1^2 - 1 \cdot 2 + 2^2 = 1 - 2 + 4 = 3 \]

Thus, \( a = 1 \) and \( b = 2 \) works, and \( 3^2 = 1^3 + 2^3 \).

Therefore, the only prime number \( p \) such that \( p^2 \) can be written as the sum of cubes of two positive integers is \( p = 3 \).

The final answer is \( \boxed{ p = 3 } \)