Practice Problems

Problem of the Day: Integer Square Root — keep your streak alive!

Practice Problems — number-theory

#ProblemTopicsDifficulty
152 GCD of Everything math number-theory 1100
143 Distinct Prime Factors math number-theory 1200
140 Is It Prime math number-theory 1300
141 Count the Primes math number-theory 1300
142 Largest Prime Factor math number-theory 1300
144 Prime Factorization math number-theory 1300
145 Count the Divisors math number-theory 1300
146 Sum of Divisors math number-theory 1400
149 Goldbach Split math number-theory 1400
150 Twin Prime Pairs math number-theory 1400
148 The Next Prime math number-theory 1500
589 Prime Power in a Factorial number-theory 1500
156 Euler's Totient math number-theory 1600
650 All Inverses at Once number-theory 1600
436 Two Remainder Conditions math number-theory 1700
647 Sum of Remainders number-theory 1700
580 Sum of Floor Divisions number-theory 1800
645 Sum of GCDs with N number-theory 1900
646 Coprime to N in a Range number-theory 1900
649 Lattice Points Under a Line number-theory 1900
651 Primitive Right Triangles number-theory 2000
578 Coprime Pairs number-theory mobius 2100
579 Sum of Pairwise GCDs number-theory 2100
582 Binomial Modulo Small Prime combinatorics number-theory 2100
648 The K-th Squarefree Number binary-search number-theory mobius 2100
935 Matrix Determinant mod p number-theory linear-algebra 2100
575 System of Remainders number-theory 2200
586 Counting Necklaces combinatorics number-theory 2200
588 Two Squares number-theory 2200
571 Factor the Giant number-theory pollard-rho 2300
574 Solve the Exponent number-theory 2300
587 Find a Primitive Root number-theory 2300
583 Square Root Modulo a Prime number-theory 2400
937 Power Tower Modulo number-theory 2400