I would now like to confront you with another question: Is it correct that for some time now the number 1 may no longer be considered a prime number?

The definition of a prime number is the following one:

- "A prime number is a natural number greater than 1 that is not a product of two smaller natural numbers."

Wikipedia wrote about the problem of the number 1 and the prime numbers:

Source: https://en.wikipedia.org/wiki/Prime_num ... ity_of_one .Wikipedia wrote:Primality of one.

Most early Greeks did not even consider 1 to be a number,[35][36] so they could not consider its primality. A few mathematicians from this time also considered the prime numbers to be a subdivision of the odd numbers, so they also did not consider 2 to be prime. However, Euclid and a majority of the other Greek mathematicians considered 2 as prime. The medieval Islamic mathematicians largely followed the Greeks in viewing 1 as not being a number.[35] By the Middle Ages and Renaissance mathematicians began treating 1 as a number, and some of them included it as the first prime number.[37] In the mid-18th century Christian Goldbach listed 1 as prime in his correspondence with Leonhard Euler; however, Euler himself did not consider 1 to be prime.[38] In the 19th century many mathematicians still considered 1 to be prime,[39] and lists of primes that included 1 continued to be published as recently as 1956.[40][41]

If the definition of a prime number were changed to call 1 a prime, many statements involving prime numbers would need to be reworded in a more awkward way. For example, the fundamental theorem of arithmetic would need to be rephrased in terms of factorizations into primes greater than 1, because every number would have multiple factorizations with different numbers of copies of 1.[39] Similarly, the sieve of Eratosthenes would not work correctly if it handled 1 as a prime, because it would eliminate all multiples of 1 (that is, all other numbers) and output only the single number 1.[41] Some other more technical properties of prime numbers also do not hold for the number 1: for instance, the formulas for Euler's totient function or for the sum of divisors function are different for prime numbers than they are for 1.[42] By the early 20th century, mathematicians began to agree that 1 should not be listed as prime, but rather in its own special category as a "unit".[39]

Sieve of Eratosthenes (without 1):

Gaussian prime numbers with norm less than_500