800 (number)

"Eight hundred" redirects here. For the film, seeThe Eight Hundred.For the year, see800.For other uses, see800 (disambiguation).

← 799 800 801 →
List of numbers Integers ←0100200300400500600700800900→
Cardinal	eight hundred
Ordinal	800th (eight hundredth)
Factorization	25× 52
Greek numeral	Ω´
Roman numeral	DCCC
Binary	11001000002
Ternary	10021223
Senary	34126
Octal	14408
Duodecimal	56812
Hexadecimal	32016
Armenian	Պ
Hebrew	ת "ת / ף
Babylonian cuneiform	𒌋𒐗⟪
Egyptian hieroglyph	𓍩

800(eight hundred) is thenatural numberfollowing799and preceding801.

It is the sum of four consecutive primes (193 + 197 + 199 + 211). It is aHarshad number,anAchilles numberand the area of asquarewith diagonal 40.

Integers from 801 to 899

800s

Main article:801 (number)

• 801 = 3²× 89, Harshad number, number of clubs patterns appearing in 50 × 50 coins
• 802 = 2 × 401, sum of eight consecutive primes (83 + 89 + 97 + 101 + 103 + 107 + 109 + 113),nontotient,happy number,sum of 4 consecutive triangular numbers(171 + 190 + 210 + 231)
• 803 = 11 × 73, sum of three consecutive primes (263 + 269 + 271), sum of nine consecutive primes (71 + 73 + 79 + 83 + 89 + 97 + 101 + 103 + 107), Harshad number, number of partitions of 34 into Fibonacci parts
• 804 = 2²× 3 × 67, nontotient, Harshad number,refactorable number
  • "The 804" is a local nickname for theGreater Richmond Regionof the U.S. state ofVirginia,derived fromits telephone area code(although the area code covers a larger area).
• 805 = 5 × 7 × 23,sphenic number,number of partitions of 38 into nonprime parts
• 806 = 2 × 13 × 31,sphenic number,nontotient, totient sum for first 51 integers,happy number,Phi(51)
• 807 = 3 × 269, antisigma(42)
• 808 = 2³× 101,refactorable number,strobogrammatic number
• 809 = prime number,Sophie Germain prime,Chen prime,Eisenstein primewith no imaginary part

810s

"811 (number)" redirects here. For the phone number, see8-1-1.For other topics, see811 (disambiguation).

• 810 = 2 × 3⁴× 5, Harshad number, number of distinct reduced words of length 5 in the Coxeter group of "Apollonian reflections" in three dimensions,number of non-equivalent ways of expressing 100,000 as the sum of two prime numbers
• 811 = prime number, twin prime, sum of five consecutive primes (151 + 157 + 163 + 167 + 173), Chen prime,happy number,largestminimal primein base 9, theMertens functionof 811 returns 0
• 812 = 2²× 7 × 29,admirable number,pronic number,balanced number,the Mertens function of 812 returns 0
• 813 = 3 × 271,blum integer(sequenceA016105in theOEIS)
• 814 = 2 × 11 × 37, sphenic number, the Mertens function of 814 returns 0, nontotient, number of fixedhexahexes.
• 815 = 5 × 163, number of graphs with 8 vertices and a distinguished bipartite block
• 816 = 2⁴× 3 × 17,tetrahedral number,Padovan number,Zuckerman number
• 817 = 19 × 43, sum of three consecutive primes (269 + 271 + 277),centered hexagonal number
• 818 = 2 × 409, nontotient,strobogrammatic number
• 819 = 3²× 7 × 13,square pyramidal number

820s

• 820 = 2²× 5 × 41,triangular number,smallest triangular number that starts with the digit 8Harshad number,happy number,repdigit (1111) in base 9
• 821 = prime number,twin prime,Chen prime, Eisenstein prime with no imaginary part, lazy caterer number (sequenceA000124in theOEIS),prime quadrupletwith 823, 827, 829
• 822 = 2 × 3 × 137, sum of twelve consecutive primes (43 + 47 + 53 + 59 + 61 + 67 + 71 + 73 + 79 + 83 + 89 + 97), sphenic number, member of theMian–Chowla sequence
• 823 = prime number,twin prime,lucky prime,the Mertens function of 823 returns 0, prime quadruplet with 821, 827, 829
• 824 = 2³× 103,refactorable number,sum of ten consecutive primes (61 + 67 + 71 + 73 + 79 + 83 + 89 + 97 + 101 + 103), the Mertens function of 824 returns 0, nontotient
• 825 = 3 × 5²× 11,Smith number,the Mertens function of 825 returns 0, Harshad number
• 826 = 2 × 7 × 59, sphenic number, number of partitions of 29 into parts each of which is used a different number of times
• 827 = prime number,twin prime,part of prime quadruplet with {821, 823, 829}, sum of seven consecutive primes (103 + 107 + 109 + 113 + 127 + 131 + 137), Chen prime, Eisenstein prime with no imaginary part, strictly non-palindromic number
• 828 = 2²× 3²× 23, Harshad number, triangular matchstick number
• 829 = prime number,twin prime,part of prime quadruplet with {827, 823, 821}, sum of three consecutive primes (271 + 277 + 281), Chen prime,centered triangular number

830s

• 830 = 2 × 5 × 83, sphenic number, sum of four consecutive primes (197 + 199 + 211 + 223), nontotient, totient sum for first 52 integers
• 831 = 3 × 277, number of partitions of 32 into at most 5 parts
• 832 = 2⁶× 13, Harshad number, member of the sequence Horadam(0, 1, 4, 2)
• 833 = 7²× 17,octagonal number(sequenceA000567in theOEIS), acentered octahedral number
• 834 = 2 × 3 × 139,cake number,sphenic number, sum of six consecutive primes (127 + 131 + 137 + 139 + 149 + 151), nontotient
• 835 = 5 × 167,Motzkin number

Main article:836 (number)

• 836 = 2²× 11 × 19,weird number
• 837 = 3³× 31, the 36th generalized heptagonal number
• 838 = 2 × 419, palindromic number, number of distinct products ijk with 1 <= i<j<k <= 23
• 839 = prime number,safe prime,sum of five consecutive primes (157 + 163 + 167 + 173 + 179), Chen prime, Eisenstein prime with no imaginary part,highly cototient number

840s

Main article:840 (number)

• 840 = 2³× 3 × 5 × 7,highly composite number,smallest number divisible by the numbers 1 to 8 (lowest common multiple of 1 to 8), sparsely totient number,Harshad number in base 2 through base 10,idoneal number,balanced number,sum of a twin prime (419 + 421). With 32 distinct divisors, it is the number below1000with the largest amount of divisors.
• 841 = 29²= 20²+ 21²,sum of three consecutive primes (277 + 281 + 283), sum of nine consecutive primes (73 + 79 + 83 + 89 + 97 + 101 + 103 + 107 + 109),centered square number,centered heptagonal number,centered octagonal number
• 842 = 2 × 421, nontotient, 842!! - 1 is prime,number of series-reduced trees with 18 nodes
• 843 = 3 × 281,Lucas number
• 844 = 2²× 211, nontotient, smallest 5 consecutive integers which are not squarefree are: 844 = 2²× 211, 845 = 5 × 13²,846 = 2 × 3²× 47, 847 = 7 × 11²and 848 = 2⁴× 53
• 845 = 5 × 13²,concentric pentagonal number,number of emergent parts in all partitions of 22
• 846 = 2 × 3²× 47, sum of eight consecutive primes (89 + 97 + 101 + 103 + 107 + 109 + 113 + 127), nontotient, Harshad number
• 847 = 7 × 11²,happy number,number of partitions of 29 that do not contain 1 as a part
• 848 = 2⁴× 53,untouchable number
• 849 = 3 × 283, the Mertens function of 849 returns 0,blum integer

850s

• 850 = 2 × 5²× 17, the Mertens function of 850 returns 0, nontotient, the sum of the squares of the divisors of 26 is 850 (sequencea001157in theOEIS). The maximum possibleFair Isaac credit score,country calling code for North Korea
• 851 = 23 × 37, number of compositions of 18 into distinct parts
• 852 = 2²× 3 × 71,pentagonal number,Smith number
  • country calling code for Hong Kong
• 853 = prime number,Perrin number,theMertens functionof 853 returns 0, average of first 853 prime numbers is an integer (sequenceA045345in theOEIS), strictly non-palindromic number, number of connected graphs with 7 nodes
  • country calling code for Macau
• 854 = 2 × 7 × 61,sphenic number,nontotient, number of unlabeled planar trees with 11 nodes
• 855 = 3²× 5 × 19,decagonal number,centered cube number
  • country calling code for Cambodia
• 856 = 2³× 107,nonagonal number,centered pentagonal number,happy number,refactorable number
  • country calling code for Laos
• 857 = prime number, sum of three consecutive primes (281 + 283 + 293), Chen prime, Eisenstein prime with no imaginary part
• 858 = 2 × 3 × 11 × 13,Giuga number
• 859 = prime number, number of planar partitions of 11,prime index prime

860s

• 860 = 2²× 5 × 43, sum of four consecutive primes (199 + 211 + 223 + 227), Hoax number
• 861 = 3 × 7 × 41, sphenic number, triangular number,hexagonal number,Smith number
• 862 = 2 × 431, lazy caterer number (sequenceA000124in theOEIS)
• 863 = prime number, safe prime,sum of five consecutive primes (163 + 167 + 173 + 179 + 181), sum of seven consecutive primes (107 + 109 + 113 + 127 + 131 + 137 + 139), Chen prime, Eisenstein prime with no imaginary part, index of prime Lucas number
• 864 = 2⁵× 3³,Achilles number,sum of a twin prime (431 + 433), sum of six consecutive primes (131 + 137 + 139 + 149 + 151 + 157), Harshad number
• 865 = 5 × 173,
• 866 = 2 × 433, nontotient, number of one-sidednoniamonds,number of cubes of edge length 1 required to make a hollow cube of edge length 13
• 867 = 3 × 17²,number of 5-chromatic simple graphs on 8 nodes
• 868 = 2²× 7 × 31 =J₃(10),nontotient
• 869 = 11 × 79, the Mertens function of 869 returns 0

870s

• 870 = 2 × 3 × 5 × 29, sum of ten consecutive primes (67 + 71 + 73 + 79 + 83 + 89 + 97 + 101 + 103 + 107), pronic number,nontotient, sparsely totient number,Harshad number
  • This number is themagic constantofn×nnormalmagic squareandn-queens problemforn= 12.
• 871 = 13 × 67, thirteenthtridecagonal number
• 872 = 2³× 109,refactorable number,nontotient, 872! + 1 isprime
• 873 = 3²× 97, sum of the first six factorials from 1
• 874 = 2 × 19 × 23,sphenic number,sum of the first twenty-three primes, sum of the first seven factorials from 0, nontotient, Harshad number,happy number
• 875 = 5³× 7, unique expression as difference of positive cubes:10³– 5³
• 876 = 2²× 3 × 73, generalized pentagonal number
• 877 = prime number,Bell number,Chen prime, the Mertens function of 877 returns 0, strictly non-palindromic number,prime index prime
• 878 = 2 × 439, nontotient, number of Pythagorean triples with hypotenuse < 1000.
• 879 = 3 × 293, number ofregular hypergraphsspanning 4 vertices,candidateLychrelseed number

880s

Main article:880 (number)

• 880 = 2⁴× 5 × 11 = 11!!!,Harshad number; 148-gonal number;the number ofn×nmagic squaresfor n = 4.
  • country calling code for Bangladesh

Main article:881 (number)

• 881 = prime number,twin prime,sum of nine consecutive primes (79 + 83 + 89 + 97 + 101 + 103 + 107 + 109 + 113), Chen prime, Eisenstein prime with no imaginary part,happy number
• 882 = 2 × 3²× 7²=${\binom {9}{5}}_{2}$atrinomial coefficient,Harshad number, totient sum for first 53 integers, area of a square with diagonal 42
• 883 = prime number,twin prime,lucky prime, sum of three consecutive primes (283 + 293 + 307), the Mertens function of 883 returns 0
• 884 = 2²× 13 × 17, the Mertens function of 884 returns 0, number of points on surface of tetrahedron with sidelength 21
• 885 = 3 × 5 × 59,sphenic number,number of series-reduced rooted trees whose leaves are integer partitions whose multiset union is an integer partition of 7.
• 886 = 2 × 443, the Mertens function of 886 returns 0
  • country calling code for Taiwan
• 887 = prime number followed by primalgapof 20, safe prime,Chen prime, Eisenstein prime with no imaginary part

Main article:888 (number)

• 888 = 2³× 3 × 37, sum of eight consecutive primes (97 + 101 + 103 + 107 + 109 + 113 + 127 + 131), Harshad number,strobogrammatic number,happy number,888!! - 1 is prime
• 889 = 7 × 127, the Mertens function of 889 returns 0

890s

• 890 = 2 × 5 × 89 = 19²+ 23²(sum of squares of two successive primes),sphenic number, sum of four consecutive primes (211 + 223 + 227 + 229), nontotient
• 891 = 3⁴× 11, sum of five consecutive primes (167 + 173 + 179 + 181 + 191),octahedral number
• 892 = 2²× 223, nontotient, number of regions formed by drawing the line segments connecting any two perimeter points of a 6 times 2 grid of squares likethis(sequenceA331452in theOEIS).
• 893 = 19 × 47, the Mertens function of 893 returns 0
  • Considered an unlucky number inJapan,because its digits read sequentially are the literal translation ofyakuza.
• 894 = 2 × 3 × 149, sphenic number, nontotient
• 895 = 5 × 179, Smith number,Woodall number,the Mertens function of 895 returns 0
• 896 = 2⁷× 7,refactorable number,sum of six consecutive primes (137 + 139 + 149 + 151 + 157 + 163), the Mertens function of 896 returns 0
• 897 = 3 × 13 × 23, sphenic number, cullen number (sequenceA002064in theOEIS)
• 898 = 2 × 449, the Mertens function of 898 returns 0, nontotient
• 899 = 29 × 31 (atwin primeproduct),happy number,smallest number with digitsum 26,number of partitions of 51 into prime parts