800 (number)

800 (eight hundred) is the natural number following 799 and preceding 801.

Cardinal 800
eight hundred
Ordinal 800th
eight hundredth
Factorization 2^5 \cdot 5^2
Roman numeral DCCC
Roman numeral (Unicode) DCCC, dccc
Binary 1100100000
Octal 1440
Duodecimal 568
Hexadecimal 320

It is the sum of four consecutive primes (193 + 197 + 199 + 211). It is a Harshad number.


801 = 32 × 89, Harshad number


802 = 2 × 401, sum of eight consecutive primes (83 + 89 + 97 + 101 + 103 + 107 + 109 + 113), nontotient


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


804 = 22 × 3 × 67, nontotient, Harshad number


805 = 5 × 7 × 23


806 = 2 × 13 × 31, sphenic number, nontotient, totient sum for first 51 integers


807 = 3 × 269


808 = 23 × 101, strobogrammatic number


809 prime number, Sophie Germain prime, Chen prime, Eisenstein prime with no imaginary part


810 = 2 × 34 × 5, Harshad number


811 prime number, sum of five consecutive primes (151 + 157 + 163 + 167 + 173), Chen prime, Mertens function(811) returns 0


812 = 22 × 7 × 29, pronic number, Mertens function(812) returns 0


813 = 3 × 271


814 = 2 × 11 × 37, sphenic number, Mertens function(814) returns 0, nontotient


815 = 5 × 163


816 = 24 × 3 × 17, tetrahedral number, member of the Padovan sequence, Zuckerman number


817 = 19 × 43, sum of three consecutive primes (269 + 271 + 277), centered hexagonal number


818 = 2 × 409, nontotient


819 = 32 × 7 × 13, square pyramidal number


820 = 22 × 5 × 41, triangular number, Harshad number


821 prime number, twin prime, Eisenstein prime with no imaginary part, prime quadruplet with 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 the Mian–Chowla sequence


823 prime number, twin prime, Mertens function(823) returns 0, prime quadruplet with 821, 827, 829


824 = 23 × 103, sum of ten consecutive primes (61 + 67 + 71 + 73 + 79 + 83 + 89 + 97 + 101 + 103), Mertens function(824) returns 0, nontotient


825 = 3 × 52 × 11, Smith number, Mertens function(825) returns 0, Harshad number


826 = 2 × 7 × 59, sphenic number


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


829 prime number, twin prime, part of prime quadruplet with {827, 823, 821}, sum of three consecutive primes (271 + 277 + 281), Chen prime


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


832 = 26 × 13, Harshad number


833 = 72 × 17


834 = 2 × 3 × 139, sphenic number, sum of six consecutive primes (127 + 131 + 137 + 139 + 149 + 151), nontotient


835 = 5 × 167, Motzkin number


836 = 22 × 11 × 19, weird number


837 = 33 × 31


838 = 2 × 419


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


840 = 23 × 3 × 5 × 7, highly composite number, smallest numbers divisible by the numbers 1 to 8, sparsely totient number, Harshad number in base 2 through base 10


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


843 = 3 × 281


844 = 22 × 211, nontotient


845 = 5 × 132


846 = 2 × 32 × 47, sum of eight consecutive primes (89 + 97 + 101 + 103 + 107 + 109 + 113 + 127), nontotient, Harshad number


847 = 7 × 112


848 = 24 × 53


849 = 3 × 283, Mertens function(849) returns 0


850 = 2 × 52 × 17, Mertens function(850) returns 0, nontotient, the maximum possible Fair Isaac credit score.


851 = 23 × 37


852 = 22 × 3 × 71, Smith number


853 prime number, Mertens function(853) returns 0, average of first 853 prime numbers is an integer (sequence A045345 in OEIS), strictly non-palindromic number


854 = 2 × 7 × 61, nontotient


855 = 32 × 5 × 19, decagonal number, centered cube number


856 = 23 × 107, nonagonal number, centered pentagonal number


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


860 = 22 × 5 × 43, sum of four consecutive primes (199 + 211 + 223 + 227)


861 = 3 × 7 × 41, sphenic number, triangular number, hexagonal number, Smith number


862 = 2 × 431


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


864 = 25 × 33, 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


867 = 3 × 172


868 = 22 × 7 × 31, nontotient


869 = 11 × 79, Mertens function(869) returns 0


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 the magic constant of n×n normal magic square and n-queens problem for n = 12.


871 = 13 × 67


872 = 23 × 109, nontotient


873 = 32 × 97, sum of the first six factorials from 1


874 = 2 × 19 × 23, sum of the first twenty-three primes, sum of the first seven factorials from 0, nontotient, Harshad number


875 = 53 × 7


876 = 22 × 3 × 73


877 prime number, Bell number, Chen prime, Mertens function(877) returns 0, strictly non-palindromic number.


878 = 2 × 439, nontotient


879 = 3 × 293


880 = 24 × 5 × 11, Harshad number; 148-gonal number; the number of n×n magic squares for n = 4.


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


882 = 2 × 32 × 72, Harshad number, totient sum for first 53 integers


883 prime number, twin prime, sum of three consecutive primes (283 + 293 + 307), Mertens function(883) returns 0


884 = 22 × 13 × 17, Mertens function(884) returns 0


885 = 3 × 5 × 59, sphenic number


886 = 2 × 443, Mertens function(886) returns 0


887 prime number followed by primal gap of 20, safe prime, Chen prime, Eisenstein prime with no imaginary part


888 = 23 × 3 × 37, sum of eight consecutive primes (97 + 101 + 103 + 107 + 109 + 113 + 127 + 131), Harshad number.


889 = 7 × 127, Mertens function(889) returns 0


890 = 2 × 5 × 89, 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


893 = 19 × 47, Mertens function(893) returns 0


894 = 2 × 3 × 149, sphenic number, nontotient


895 = 5 × 179, Smith number, Woodall number, Mertens function(895) returns 0


896 = 27 × 7, sum of six consecutive primes (137 + 139 + 149 + 151 + 157 + 163), Mertens function(896) returns 0


897 = 3 × 13 × 23, sphenic number


898 = 2 × 449, Mertens function(898) returns 0, nontotient


899 = 29 × 31