What is known about the sum $\sum\frac1{p^p}$ of reciprocals of primes raised to themselves?

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Consider the following series:

$$\sum_{p\in\mathcal{P}}\frac{1}{p^p}$$

where $\mathcal{P}$ is the set of all prime numbers: $\mathcal{P}=\{2,3,5,7,11,13,\ldots\}$. My question is:

Is this a known series? In case it is, what is it's name in literature?

With a simple comparison, we conclude that it is convergent and:

$$0\leq \frac{1}{p^p}\leq \frac{1}{p^2}\Rightarrow 0\leq\sum_{p\in\mathcal{P}}\frac{1}{p^p}\leq\sum_{p\in\mathcal{P}}\frac{1}{p^2}<\sum_{n=2}^{\infty}\frac{1}{n^2}=\frac{\pi^2}{6}-1\approx 0.64493$$

and for $p\in\{2,3,5,7,11,13\}=\mathcal{P}_{13}$ my calculator outputed:

$$\sum_{p\in\mathcal{P}_{13}}\frac{1}{p^p}\approx 0.287358251$$

But what else can we say about it? Is it a rational number? In case it isn't rational, is it algebraic (and if it is what can we say about the minimal polynomial)?