13

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Summary

Factorization

The number 13 is a prime number.

Prime-generating polynomials

Below are some polynomials that give prime numbers for small input values, which give the value 13 for suitable input choice.

Polynomial	Degree	Some values for which it generates primes	Input value $n$ at which it generates 13
$n^{2}-n+11$	2	all numbers 1-10, because 11 is one of the lucky numbers of Euler.	2

Multiples

Interesting multiples

Number	Prime factorization	What's interesting about it
1105	5 times 13 times 17	second Carmichael number, i.e., absolute pseudoprime
1729	7 times 13 times 19	third Carmichael number, i.e., absolute pseudoprime
2821	7 times 13 times 31	fifth Carmichael number, i.e., absolute pseudoprime