800 801 → Factorization 2× 5 Binary 11001000002 | Cardinal eight hundred Roman numeral DCCC | |
Ordinal 800th
(eight hundredth) | ||
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
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 {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 (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
853 prime number, Perrin number, the Mertens function of 853 returns 0, average of first 853 prime numbers is an integer (sequence A045345 in the OEIS), strictly non-palindromic number, number of connected graphs with 7 nodes
854 = 2 × 7 × 61, nontotient
855 = 32 × 5 × 19, decagonal number, centered cube number
856 = 23 × 107, nonagonal number, centered pentagonal number, happy 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, 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.
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
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, strobogrammatic 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