Selected numbers

• 50000 – round number
• 50625 – smallest fourth power that can be expressed as the sum of only five distinct fourth powers
• 51641 – Markov number
  Markov number
  A Markov number or Markoff number is a positive integer x, y or z that is part of a solution to the Markov Diophantine equationx^2 + y^2 + z^2 = 3xyz,\,studied by .The first few Markov numbers are...
  
  
• 51984 – . the smallest square to the sum of only five distinct fourth powers.
• 52375 – Address of the office building in the Counter-Strike
  Counter-Strike
  Counter-Strike is a tactical first-person shooter video game developed by Valve Corporation which originated from a Half-Life modification by Minh "Gooseman" Le and Jess "Cliffe" Cliffe...
  
   map Cs Office
• 52633 – Carmichael number
• 53016 – pentagonal pyramidal number
  Pentagonal pyramidal number
  A pentagonal pyramidal number is a figurate number that represents the number of objects in a pyramid with a pentagonal base. The nth pentagonal pyramidal number is equal to the sum of the first n pentagonal numbers....
  
  
• 53361 – sum of the cubes of the first 21 positive integers
• 54205 – Zeisel number
• 54748 – equal to the sum of the fifth powers of its digits
• 54901 – chiliagonal number
• 55440 – colossally abundant number
  Colossally abundant number
  In mathematics, a colossally abundant number is a natural number that, in some rigorous sense, has a lot of divisors...
  
  
• 55459 – one of six remaining Seventeen or Bust
  Seventeen or Bust
  Seventeen or Bust is a distributed computing project started in March 2002 to solve the last seventeen cases in the Sierpinski problem.-Goals:...
  
   numbers in the Sierpinski problem
• 55860 – harmonic divisor number
  Harmonic divisor number
  In mathematics, a harmonic divisor number, or Ore number , is a positive integer whose divisors have a harmonic mean that is an integer. The first few harmonic divisor numbers are...
  
  
• 56011 – Wedderburn-Etherington number
  Wedderburn-Etherington number
  In graph theory, the Wedderburn–Etherington numbers, named for Ivor Malcolm Haddon Etherington and Joseph Wedderburn, count how many weak binary trees can be constructed: that is, the number of trees for which each graph vertex is adjacent to no more than three other such vertices, for a...
  
  
• 56092 – the number of groups of order 256, see http://www-public.tu-bs.de:8080/~beick/soft/small/small.html
• 56448 – pentagonal pyramidal number
  Pentagonal pyramidal number
  A pentagonal pyramidal number is a figurate number that represents the number of objects in a pyramid with a pentagonal base. The nth pentagonal pyramidal number is equal to the sum of the first n pentagonal numbers....
  
  
• 58367 – smallest integer that cannot be expressed as a sum of fewer than 1079 tenth powers
• 58786 – Catalan number
  Catalan number
  In combinatorial mathematics, the Catalan numbers form a sequence of natural numbers that occur in various counting problems, often involvingrecursively defined objects...
  
  
• 59049 –
• 59081 – Zeisel number