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800 (eight hundred) is the natural number following 799 and preceding 801. 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, happy number ---- 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 * "The 804" is a local nickname for the Greater Richmond Region of the U.S. state of Virginia, derived from its telephone area code (although the area code covers a larger area). ---- 805 = 5 × 7 × 23 ---- 806 = 2 × 13 × 31, sphenic number, nontotient, totient sum for first 51 integers, happy number ---- 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, happy number, the Mertens function of 811 returns 0 ---- 812 = 22 × 7 × 29, pronic number, the Mertens function of 812 returns 0 ---- 813 = 3 × 271 ---- 814 = 2 × 11 × 37, sphenic number, the Mertens function of 814 returns 0, nontotient ---- 815 = 5 × 163 ---- 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 ---- 820 = 22 × 5 × 41, triangular number, Harshad number, happy number, repdigit (1111) in base 9 ---- 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, the Mertens function of 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), the Mertens function of 824 returns 0, nontotient ---- 825 = 3 × 52 × 11, Smith number, the Mertens function 825 returns 0, Harshad number ---- 826 = 2 × 7 × 59, sphenic number ---- 827 prime number, twin prime, part of prime quadruplet with , 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 , 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 (lowest common multiple of 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, Lucas number ---- 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, happy number ---- 848 = 24 × 53 ---- 849 = 3 × 283, the Mertens function of 849 returns 0 ---- 850 = 2 × 52 × 17, the Mertens function 850 returns 0, nontotient, the maximum possible Fair Isaac credit score, country calling code for North Korea ---- 851 = 23 × 37 ---- 852 = 22 × 3 × 71, pentagonal number, Smith number *country calling code for Hong Kong ---- 853 prime number, Perrin number, the Mertens function of 853 returns 0, average of first 853 prime numbers is an integer , strictly non-palindromic number, number of connected graphs with 7 nodes *country calling code for Macau ---- 854 = 2 × 7 × 61, nontotient ---- 855 = 32 × 5 × 19, decagonal number, centered cube number *country calling code for Cambodia ---- 856 = 23 × 107, nonagonal number, centered pentagonal number, happy 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 ---- 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, the 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, happy number ---- 875 = 53 × 7 ---- 876 = 22 × 3 × 73 ---- 877 prime number, Bell number, Chen prime, the Mertens function of 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. *country calling code for Bangladesh ---- 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), the Mertens function of 883 returns 0, happy number ---- 884 = 22 × 13 × 17, the Mertens function 884 returns 0 ---- 885 = 3 × 5 × 59, sphenic number ---- 886 = 2 × 443, the Mertens function of 886 returns 0 *country calling code for Taiwan ---- 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, the Mertens function of 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, the Mertens function 893 returns 0 ---- 894 = 2 × 3 × 149, sphenic number, nontotient ---- 895 = 5 × 179, Smith number, Woodall number, the Mertens function 895 returns 0 ---- 896 = 27 × 7, sum of six consecutive primes (137 + 139 + 149 + 151 + 157 + 163), the Mertens function 896 returns 0 ---- 897 = 3 × 13 × 23, sphenic number ---- 898 = 2 × 449, the Mertens function of 898 returns 0, nontotient ---- 899 = 29 × 31, happy number 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「800 (number)」の詳細全文を読む スポンサード リンク
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