The category of sets is a fundamental category in category theory, and it is often used as an example to illustrate the basic concepts of the theory.

The power set functor is a functor that maps a set $X$ to the set of all subsets of $X$, denoted by $P(X)$.

The Fundamental Theorem of Arithmetic states that every positive integer can be written as a product of prime numbers, and that this factorization is unique up to the order of the factors.

Goldbach's Conjecture states that every even number greater than 2 can be written as the sum of two primes. This conjecture has been proven for all even numbers up to 4³10^{18}, but it remains unproven in general.

Euclid's Theorem states that there are infinitely many prime numbers. This theorem was first proven by Euclid in his book Elements, and it is one of the most important results in number theory.

The Riemann Hypothesis states that the Riemann zeta function has no zeros on the line $Re(s) = 1/2$. This hypothesis is one of the most important unsolved problems in mathematics, and it has implications for many areas of mathematics, including number theory, analysis, and physics.

The P versus NP problem asks whether there exists a polynomial-time algorithm for determining whether a given integer is prime. This problem is one of the most important unsolved problems in computer science, and it has implications for many areas of computer science, including cryptography, optimization, and artificial intelligence.

The Fundamental Theorem of Arithmetic states that every integer greater than 1 can be written as a product of powers of distinct primes, and that this factorization is unique up to the order of the factors.

The Hardy–Littlewood conjecture states that there are infinitely many twin primes, which are pairs of prime numbers that differ by 2.

Euler's product formula states that the sum of the reciprocals of the primes diverges.

Lagrange's four-square theorem states that every positive integer can be written as a sum of four squares.

The Fundamental Theorem of Arithmetic states that every integer greater than 1 can be written as a product of powers of distinct primes, and that this factorization is unique up to the order of the factors.

Euclid's Theorem states that there are infinitely many prime numbers. This theorem was first proven by Euclid in his book Elements, and it is one of the most important results in number theory.

Goldbach's Conjecture states that every even number greater than 2 can be written as the sum of two primes. This conjecture has been proven for all even numbers up to 4³10^{18}, but it remains unproven in general.

The Riemann Hypothesis states that the Riemann zeta function has no zeros on the line $Re(s) = 1/2$. This hypothesis is one of the most important unsolved problems in mathematics, and it has implications for many areas of mathematics, including number theory, analysis, and physics.