252 (number)

252 (two hundred [and] fifty-two) is the natural number following 251 and preceding 253.

In mathematics

252 is:

• the central binomial coefficient , the largest one divisible by all coefficients in the previous line^[1]
• a Harshad number in base 10.
• , where is the Ramanujan tau function.^[2]
• , where is the function that sums the cubes of the divisors of its argument:^[3]

• a practical number,^[4]
• a refactorable number,^[5]
• a hexagonal pyramidal number.^[6]
• a member of the Mian-Chowla sequence.^[7]

There are 252 points on the surface of a cuboctahedron of radius five in the fcc lattice,^[8] 252 ways of writing the number 4 as a sum of six squares of integers,^[9] 252 ways of choosing four squares from a 4×4 chessboard up to reflections and rotations,^[10] and 252 ways of placing four pieces on a Connect Four board.^[11]

References