4 ms·
Okay.. so 1 should neither be prime nor composite. Because - a) 1 cannot be written as a product of two different factors : ruling out 1 to be composite b) 1 h
by animeshk 9y ago
Okay.. so 1 should neither be prime nor composite. Because -
a) 1 cannot be written as a product of two different factors : ruling out 1 to be composite
b) 1 has only 1 positive divisor : ruling it out to be prime
That's indeed a special case which can be mentioned in the article.
- mbid 9y agoI would simply not define "prime" or "composite" for 1, yes. If you check abstract algebra books (or wikipedia [1]), you'll usually find definitions along the lines of "a non-invertible, non-zero element is prime if and only if ...", and the nice thing about this definition is that it is a useful concept in more general structures than just natural numbers, namely (semi)rings. [1](https://en.wikipedia.org/wiki/Prime_element https://en.wikipedia.org/wiki/Prime_element)