The number –1 is a reflection relative to the number +1. With the imaginary unit you can express it as i² = –1 or with Euler's identity as e^iπ = –1.

The number 0 can be divided by all other numbers and is therefore not prime.

The number 1 can also be written as e⁰ = 1 or with the imaginary unit as i⁰ = 1 and with Euler's identity as e^2iπ = 1.

The number 2 is a prime number. Because of this other even numbers can not be primes.

The number 3 is a prime number. Because of this all multiples of three can not be primes.

From the number 5 all primes have the form 6n ± 1. This way two columns develop in which twins primes occur.

After the number 24 the regularity breaks, because the number 25 comes from previous primes, because 25 = 5 × 5. You can see this happen again and again later, like with 35 = 5 × 7 and with 49 = 7 × 7 and so on.