Cardinal Cardinal number In mathematics, cardinal numbers, or cardinals for short, are a generalization of the natural numbers used to measure the cardinality of sets. The cardinality of a finite set is a natural number – the number of elements in the set. The transfinite cardinal numbers describe the sizes of infinite...	6000 six thousand
Ordinal Ordinal number In set theory, an ordinal number, or just ordinal, is the order type of a well-ordered set. They are usually identified with hereditarily transitive sets. Ordinals are an extension of the natural numbers different from integers and from cardinals...	6000th six thousandth
Factorization Factorization In mathematics, factorization or factoring is the decomposition of an object into a product of other objects, or factors, which when multiplied together give the original...
Roman numeral	M
Roman numeral (Unicode)	M, m
Binary Binary numeral system The binary numeral system, or base-2 number system, represents numeric values using two symbols, 0 and 1. More specifically, the usual base-2 system is a positional notation with a radix of 2...	1011101110000
Octal Octal The octal numeral system, or oct for short, is the base-8 number system, and uses the digits 0 to 7. Numerals can be made from binary numerals by grouping consecutive binary digits into groups of three...	13560
Duodecimal Duodecimal The duodecimal system is a positional notation numeral system using twelve as its base. In this system, the number ten may be written as 'A', 'T' or 'X', and the number eleven as 'B' or 'E'...	3580
Hexadecimal Hexadecimal In mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...	1770

Selected numbers in the range 6001–6999

• 6025 – Rhythm guitarist of the Dead Kennedys
  Dead Kennedys
  Dead Kennedys are an American punk rock band formed in San Francisco, California in 1978. The band became part of the American hardcore punk movement of the early 1980s. They gained a large underground fanbase in the international punk music scene....
  
   from June 1978 to March 1979. Full name is Carlos Cadona.
• 6028 – centered heptagonal number
  Centered heptagonal number
  A centered heptagonal number is a centered figurate number that represents a heptagon with a dot in the center and all other dots surrounding the center dot in successive heptagonal layers...
  
  
• 6047 – safe prime
  Safe prime
  A safe prime is a prime number of the form 2p + 1, where p is also a prime. The first few safe primes are...
  
  
• 6053 – Sophie Germain prime
  Sophie Germain prime
  In number theory, a prime number p is a Sophie Germain prime if 2p + 1 is also prime. For example, 23 is a Sophie Germain prime because it is a prime and 2 × 23 + 1 = 47, and 47 is also a prime number...
  
  
• 6069 – nonagonal number
• 6073 – balanced prime
• 6084 – , sum of the cubes of the first twelve integers
• 6089 – highly cototient number
  Highly cototient number
  In number theory, a branch of mathematics, a highly cototient number is a positive integer k which is above one and has more solutions to the equation...
  
  
• 6095 – magic constant
  Magic constant
  The magic constant or magic sum of a magic square is the sum of numbers in any row, column, and diagonal of the magic square. For example, the magic square shown below has a magic constant of 15....
  
   of n×n normal magic square
  Magic square
  In recreational mathematics, a magic square of order n is an arrangement of n2 numbers, usually distinct integers, in a square, such that the n numbers in all rows, all columns, and both diagonals sum to the same constant. A normal magic square contains the integers from 1 to n2...
  
   and n-Queens Problem
  Eight queens puzzle
  The eight queens puzzle is the problem of placing eight chess queens on an 8×8 chessboard so that no two queens attack each other. Thus, a solution requires that no two queens share the same row, column, or diagonal...
  
   for n = 23.
• 6101 – Sophie Germain prime
• 6105 – triangular number
  Triangular number
  A triangular number or triangle number numbers the objects that can form an equilateral triangle, as in the diagram on the right. The nth triangle number is the number of dots in a triangle with n dots on a side; it is the sum of the n natural numbers from 1 to n...
  
  
• 6113 – Sophie Germain prime
• 6131 – Sophie Germain prime
• 6143 – Thabit number
  Thabit number
  In number theory, a Thabit number, Thâbit ibn Kurrah number, or 321 number is an integer of the form 3·2n−1 for a non-negative integer n...
  
  
• 6173 – Sophie Germain prime
• 6174 – Kaprekar's constant
  6174 (number)
  6174 is known as Kaprekar's constant after the Indian mathematician D. R. Kaprekar. This number is notable for the following property:#Take any four-digit number, using at least two different digits...
  
  
• 6181 – octahedral number
  Octahedral number
  In number theory, an octahedral number is a figurate number that represents the number of spheres in an octahedron formed from close-packed spheres...
  
  
• 6200 – 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...
  
  
• 6201 – square pyramidal number
  Square pyramidal number
  In mathematics, a pyramid number, or square pyramidal number, is a figurate number that represents the number of stacked spheres in a pyramid with a square base...
  
  
• 6211 – cuban prime of the form x = y + 1
• 6216 – triangular number
• 6232 – amicable number
  Amicable number
  Amicable numbers are two different numbers so related that the sum of the proper divisors of each is equal to the other number. A pair of amicable numbers constitutes an aliquot sequence of period 2...
  
   with 6368
• 6241 – , centered octagonal number
  Centered octagonal number
  A centered octagonal number is a centered figurate number that represents an octagon with a dot in the center and all other dots surrounding the center dot in successive octagonal layers...
  
  
• 6250 – Leyland number
  Leyland number
  In number theory, a Leyland number is a number of the form xy + yx, where x and y are integers greater than 1. The first few Leyland numbers are...
  
  
• 6263 – Sophie Germain prime, balanced prime
• 6269 – Sophie Germain prime
• 6280 – decagonal number
  Decagonal number
  A decagonal number is a figurate number that represents a decagon. The n-th decagonal number is given by the formulaThe first few decagonal numbers are:...
  
  
• 6317 – balanced prime
• 6322 – centered heptagonal number
• 6323 – Sophie Germain prime, balanced prime
• 6328 – triangular number
• 6348 – 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....
  
  
• 6364 – nonagonal number
• 6367 – balanced prime
• 6368 – amicable number with 6232
• 6373 – balanced prime
• 6399 – smallest integer that cannot be expressed as a sum of fewer than 279 eighth powers
• 6400 –
• 6408 – sum of the squares of the first thirteen primes
• 6441 – triangular number
• 6449 – Sophie Germain prime
• 6466 – 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...
  
  
• 6491 – Sophie Germain prime
• 6509 – highly cototient number
• 6521 – Sophie Germain prime
• 6545 – tetrahedral number
  Tetrahedral number
  A tetrahedral number, or triangular pyramidal number, is a figurate number that represents a pyramid with a triangular base and three sides, called a tetrahedron...
  
  
• 6551 – Sophie Germain prime
• 6555 – triangular number
• 6556 – member of a Ruth-Aaron pair
  Ruth-Aaron pair
  In mathematics, a Ruth–Aaron pair consists of two consecutive integers for which the sums of the prime factors of each integer are equal:andIf only distinct prime factors are counted, the first few Ruth–Aaron pairs are:...
  
   with 6557 (first definition)
• 6557 – member of a Ruth-Aaron pair with 6556 (first definition)
• 6561 – , , perfect totient number
  Perfect totient number
  In number theory, a perfect totient number is an integer that is equal to the sum of its iterated totients. That is, we apply the totient function to a number n, apply it again to the resulting totient, and so on, until the number 1 is reached, and add together the resulting sequence of numbers;...
  
  , centered octagonal number
• 6599 – safe prime
• 6563 – Sophie Germain prime
• 6581 – Sophie Germain prime
• 6601 – Carmichael number, decagonal number
• 6623 – centered heptagonal number
• 6659 – safe prime
• 6666 – nonagonal number
• 6670 – triangular number
• 6719 – safe prime, highly cototient number
• 6724 –
• 6728 – number of domino tilings of a 6×6 checkerboard
  Checkerboard
  A checkerboard or chequerboard is a board of chequered pattern on which English draughts is played. It is an 8×8 board and the 64 squares are of alternating dark and light color, often red and black....
  
  
• 6761 – Sophie Germain prime
• 6765 – Fibonacci number
  Fibonacci number
  In mathematics, the Fibonacci numbers are the numbers in the following integer sequence:0,\;1,\;1,\;2,\;3,\;5,\;8,\;13,\;21,\;34,\;55,\;89,\;144,\; \ldots\; ....
  
  
• 6779 – safe prime
• 6786 – triangular number
• 6811 – member of a Ruth-Aaron pair with 6812 (first definition)
• 6812 – member of a Ruth-Aaron pair with 6811 (first definition)
• 6827 – safe prime
• 6863 – balanced prime
• 6880 – vampire number
  Vampire number
  In mathematics, a vampire number is a composite natural number v, with an even number of digits n, that can be factored into two integers x and y each with n/2 digits and not both with trailing zeroes, where v contains precisely all the digits from x and from y, in any order, counting multiplicity...
  
  
• 6889 – , centered octagonal number
• 6899 – Sophie Germain prime, safe prime
• 6903 – triangular number
• 6924 – magic constant
  Magic constant
  The magic constant or magic sum of a magic square is the sum of numbers in any row, column, and diagonal of the magic square. For example, the magic square shown below has a magic constant of 15....
  
   of n×n normal magic square
  Magic square
  In recreational mathematics, a magic square of order n is an arrangement of n2 numbers, usually distinct integers, in a square, such that the n numbers in all rows, all columns, and both diagonals sum to the same constant. A normal magic square contains the integers from 1 to n2...
  
   and n-Queens Problem
  Eight queens puzzle
  The eight queens puzzle is the problem of placing eight chess queens on an 8×8 chessboard so that no two queens attack each other. Thus, a solution requires that no two queens share the same row, column, or diagonal...
  
  for n = 24.
• 6929 – highly cototient number
• 6930 – decagonal number, square pyramidal number
• 6931 – centered heptagonal number
• 6975 – nonagonal number
• 6977 – balanced prime
• 6983 – Sophie Germain prime, safe prime