From Wikipedia: "The Ulam spiral, or prime spiral (in other languages also called the Ulam Cloth) is a simple method of visualizing the prime numbers that reveals the apparent tendency of certain quadratic polynomials to generate unusually large numbers of primes. It was discovered by the mathematician Stanislaw Ulam in 1963..."
How complex is it? Here goes the Complexity Map of the above image:
These are the corresponding complexity measures:
The high robustness of the image - 76.8% - means that its structure is relatively strong. This means, for example, that the image may be de-focused and still transmit most of the information it contains.
The amount of information the image transmits is nearly 154 bits.