Show me a random puzzle
 Most recent collections 


logic odd numbers numbers spheres cryptic clues crosswords advent arrows ave star numbers parabolas people maths dates cube numbers menace bases multiples geometry sequences irreducible numbers calculus shape division quadratics shapes volume routes square numbers rectangles pascal's triangle christmas differentiation triangles coordinates perfect numbers money digits 2d shapes doubling 3d shapes square roots scales integration proportion symmetry probability area angles balancing percentages grids integers sums circles factorials mean taxicab geometry colouring floors addition rugby functions prime numbers partitions graphs dodecagons books planes factors cryptic crossnumbers speed indices time algebra complex numbers regular shapes ellipses crossnumbers chalkdust crossnumber fractions multiplication chocolate folding tube maps coins lines unit fractions number squares remainders polygons probabilty wordplay cards clocks games trigonometry chess sum to infinity surds hexagons triangle numbers sport palindromes perimeter means dice averages


Show me a random puzzle
▼ show ▼

21 December

The factors of 6 (excluding 6 itself) are 1, 2 and 3. \(1+2+3=6\), so 6 is a perfect number.
Today's number is the only three digit perfect number.
© Matthew Scroggs 2019