1000 (number)

Notation

• The decimal representation for one thousand is
• * 1000—a one followed by three zeros, in the general notation;
• * 1 × 10³—in engineering notation, which for this number coincides with:
• * 1 × 10³ exactly—in scientific normalized exponential notation;
• * 1 E+3 exactly—in scientific E notation.
• The SI prefix for a thousand units is "kilo-", abbreviated to "k"—for instance, a kilogram or "kg" is a thousand grams. This is sometimes extended to non-SI contexts, such as "ka" being used as a shorthand for periods of 1000 years. In computer science, however, "kilo-" is used more loosely to mean 2 to the 10th power.
• In the SI writing style, a non-breaking space can be used as a thousands separator, i.e., to separate the digits of a number at every power of 1000.
• Multiples of thousands are occasionally represented by replacing their last three zeros with the letter "K" or "k": for instance, writing "$30k" for $30,000 or using "Y2K" to denote the Year 2000 computer problem.
• A thousand units of currency, especially dollars or pounds, are colloquially called a grand. In the United States, this is sometimes abbreviated with a "G" suffix.

  In mathematics

Numbers in the range 1001–1999

1001 to 1099

• 1001 = sphenic number, pentagonal number, pentatope number, palindromic number
• 1002 = sphenic number, Mertens function zero, abundant number, number of partitions of 22
• 1003 = the product of some prime p and the p^th prime, namely p = 17.
• 1004 = heptanacci number
• 1005 = Mertens function zero, decagonal pyramidal number
• 1006 = semiprime, product of two distinct isolated primes ; unusual number; square-free number; number of compositions of 22 into squares; sum of two distinct pentatope numbers ; number of undirected Hamiltonian paths in 4 by 5 square grid graph; record gap between twin primes; number that is the sum of 7 positive 5th powers. In decimal: equidigital number; when turned around, the number looks like a prime, 9001; its cube can be concatenated from other cubes, 1_0_1_8_1_0_8_216
• 1007 = number that is the sum of 8 positive 5th powers
• 1008 = divisible by the number of primes below it
• 1009 = smallest four-digit prime, palindromic in bases 11, 15, 19, 24 and 28:. It is also a Lucky prime and Chen prime.
• 1010 = 10³ + 10, Mertens function zero
• 1011 = the largest n such that 2ⁿ contains 101 and does not contain 11011, Harshad number in bases 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, number of partitions of 1 into reciprocals of positive integers <= 16 Egyptian fraction
• 1012 = ternary number, quadruple triangular number, number of partitions of 1 into reciprocals of positive integers <= 17 Egyptian fraction
• 1013 = Sophie Germain prime, centered square number, Mertens function zero
• 1014 = 2¹⁰-10, Mertens function zero, sum of the nontriangular numbers between successive triangular numbers 78 and 91
• 1015 = square pyramidal number
• 1016 = member of the Mian–Chowla sequence, stella octangula number, number of surface points on a cube with edge-length 14
• 1017 = generalized triacontagonal number
• 1018 = Mertens function zero, 1018¹⁶ + 1 is prime
• 1019 = Sophie Germain prime, safe prime, Chen prime
• 1020 = polydivisible number
• 1021 = twin prime with 1019. It is also a Lucky prime.
• 1022 = Friedman number
• 1023 = sum of five consecutive primes ; the number of three-dimensional polycubes with 7 cells; number of elements in a 9-simplex; highest number one can count to on one's fingers using binary; magic number used in Global Positioning System signals.
• 1024 = 32² = 4⁵ = 2¹⁰, the number of bytes in a kilobyte. 1024 is the smallest 4-digit square and also a Friedman number.
• 1025 = Proth number 2¹⁰ + 1; member of Moser–de Bruijn sequence, because its base-4 representation contains only digits 0 and 1, or it's a sum of distinct powers of 4 ; Jacobsthal-Lucas number; hypotenuse of primitive Pythagorean triangle
• 1026 = sum of two distinct powers of 2
• 1027 = sum of the squares of the first eight primes; can be written from base 2 to base 18 using only the digits 0 to 9.
• 1028 = sum of totient function for first 58 integers; can be written from base 2 to base 18 using only the digits 0 to 9; number of primes <= 2¹³.
• 1029 = can be written from base 2 to base 18 using only the digits 0 to 9.
• 1030 = generalized heptagonal number
• 1031 = exponent and number of ones for the fifth base-10 repunit prime, Sophie Germain prime, super-prime, Chen prime
• 1032 = sum of two distinct powers of 2
• 1033 = emirp, twin prime with 1031
• 1034 = sum of 12 positive 9th powers
• 1035 = 45th triangular number, hexagonal number
• 1036 = central polygonal number
• 1037 = number in E-toothpick sequence
• 1038 = even integer that is an unordered sum of two primes in exactly 40 ways
• 1039 = prime of the form 8n+7, number of partitions of 30 that do not contain 1 as a part, Chen prime, Lucky prime
• 1040 = 4⁵ + 4²: sum of distinct powers of 4. The number of pieces that could be seen in a 6 × 6 × 6× 6 Rubik's Tesseract.
• 1041 = sum of 11 positive 5th powers
• 1042 = sum of 12 positive 5th powers
• 1043 = number whose sum of even digits and sum of odd digits are even
• 1044 = sum of distinct powers of 4
• 1045 = octagonal number
• 1046 = coefficient of f
• 1047 = number of ways to split a strict composition of 18 into contiguous subsequences that have the same sum
• 1048 = number of partitions of 27 into squarefree parts
• 1049 = Sophie Germain prime, highly cototient number, Chen prime
• 1050 = 1050₈ to decimal becomes a pronic number, number of parts in all partitions of 29 into distinct parts
• 1051 = centered pentagonal number, centered decagonal number
• 1052 = sum of 9 positive 6th powers
• 1053 = triangular matchstick number
• 1054 = centered triangular number
• 1055 = sum of 12 positive 6th powers
• 1056 = pronic number
• 1057 = central polygonal number
• 1058 = sum of 4 positive 5th powers, area of a square with diagonal 46
• 1059 = number n such that n⁴ is written in the form of a sum of four positive 4th powers
• 1060 = sum of the first twenty-five primes from 2 through 97, and sixth sum of 10 consecutive primes, starting with 23 through 131.
• 1061 = emirp, twin prime with 1063, number of prime numbers between 1000 and 10000
• 1062 = number that is not the sum of two palindromes
• 1063 = super-prime, sum of seven consecutive primes ; near-wall-sun-sun prime. It is also a twin prime with 1061.
• 1064 = sum of two positive cubes
• 1065 = generalized duodecagonal
• 1066 = number whose sum of their divisors is a square
• 1067 = number of strict integer partitions of 45 in which are empty or have smallest part not dividing the other ones
• 1068 = number that is the sum of 7 positive 5th powers, total number of parts in all partitions of 15
• 1069 = emirp
• 1070 = number that is the sum of 9 positive 5th powers
• 1071 = heptagonal number
• 1072 = centered heptagonal number
• 1073 = number that is the sum of 12 positive 5th powers
• 1074 = number that is not the sum of two palindromes
• 1075 = number non-sum of two palindromes
• 1076 = number of strict trees weight 11
• 1077 = number where 7 outnumbers every other digit in the number
• 1078 = Euler transform of negative integers
• 1079 = every positive integer is the sum of at most 1079 tenth powers.
• 1080 = pentagonal number, largely composite number
• 1081 = 46th triangular number, member of Padovan sequence
• 1082 = central polygonal number
• 1083 = three-quarter square, number of partitions of 53 into prime parts
• 1084 = third spoke of a hexagonal spiral, 1084⁶⁴ + 1 is prime
• 1085 = number of partitions of n into distinct parts > or = 2
• 1086 = Smith number, sum of totient function for first 59 integers
• 1087 = super-prime, cousin prime, lucky prime
• 1088 = octo-triangular number, sum of two distinct powers of 2, number that is divisible by exactly seven primes with the inclusion of multiplicity
• 1089 = 33², nonagonal number, centered octagonal number, first natural number whose digits in its decimal representation get reversed when multiplied by 9.
• 1090 = sum of 5 positive 5th powers
• 1091 = cousin prime and twin prime with 1093
• 1092 = divisible by the number of primes below it
• 1093 = the smallest Wieferich prime, twin prime with 1091 and star number
• 1094 = sum of 9 positive 5th powers, 1094⁶⁴ + 1 is prime
• 1095 = sum of 10 positive 5th powers, number that is not the sum of two palindromes
• 1096 = hendecagonal number, number of strict solid partitions of 18
• 1097 = emirp, Chen prime
• 1098 = multiple of 9 containing digit 9 in its base-10 representation
• 1099 = number where 9 outnumbers every other digit