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

← 799 800 801 →
Cardinaleight hundred
Ordinal800th
(eight hundredth)
Factorization25× 52
Greek numeralΩ´
Roman numeralDCCC
Binary11001000002
Ternary10021223
Quaternary302004
Quinary112005
Senary34126
Octal14408
Duodecimal56812
Hexadecimal32016
Vigesimal20020
Base 36M836

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

Contents

Integers from 801 to 899Edit

800sEdit

810sEdit

820sEdit

  • 820 = 22 × 5 × 41, triangular number,[8] 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[9]
  • 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,[10] the Mertens function of 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[11]
  • 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

830sEdit

  • 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[12]

840sEdit

  • 840 = 23 × 3 × 5 × 7, highly composite number,[15] smallest numbers divisible by the numbers 1 to 8 (lowest common multiple of 1 to 8), sparsely totient number,[16] 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,[17] centered heptagonal number,[18] centered octagonal number[19]
  • 842 = 2 × 421, nontotient
  • 843 = 3 × 281, Lucas number[20]
  • 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

850sEdit

860sEdit

  • 860 = 22 × 5 × 43, sum of four consecutive primes (199 + 211 + 223 + 227)
  • 861 = 3 × 7 × 41, sphenic number, triangular number,[8] hexagonal number,[28] Smith number[10]
  • 862 = 2 × 431
  • 863 = prime number, safe prime,[13] 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 of 869 returns 0

870sEdit

  • 870 = 2 × 3 × 5 × 29, sum of ten consecutive primes (67 + 71 + 73 + 79 + 83 + 89 + 97 + 101 + 103 + 107), pronic number,[3] nontotient, sparsely totient number,[16] Harshad number
  • 871 = 13 × 67, thirteenth tridecagonal number
  • 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, unique expression as difference of positive cubes[29]: 103 - 53
  • 876 = 22 × 3 × 73
  • 877 = prime number, Bell number,[30] Chen prime, the Mertens function of 877 returns 0, strictly non-palindromic number.[11]
  • 878 = 2 × 439, nontotient
  • 879 = 3 × 293, number of regular hypergraphs spanning 4 vertices[31]

880sEdit

  • 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, happy number
  • 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
  • 884 = 22 × 13 × 17, the Mertens function of 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,[13] 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[1]
  • 889 = 7 × 127, the Mertens function of 889 returns 0

890sEdit

  • 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 of 893 returns 0
    • Considered an unlucky number in Japan, because its digits read sequentially are the literal translation of yakuza.
  • 894 = 2 × 3 × 149, sphenic number, nontotient
  • 895 = 5 × 179, Smith number,[10] Woodall number,[32] the Mertens function of 895 returns 0
  • 896 = 27 × 7, sum of six consecutive primes (137 + 139 + 149 + 151 + 157 + 163), the Mertens function of 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

ReferencesEdit

  1. ^ a b c Sloane, N. J. A. (ed.). "Sequence A000787 (Strobogrammatic numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  2. ^ Sloane, N. J. A. (ed.). "Sequence A005384 (Sophie Germain primes)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  3. ^ a b Sloane, N. J. A. (ed.). "Sequence A002378 (Oblong (or promic, pronic, or heteromecic) numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  4. ^ Sloane, N. J. A. (ed.). "Sequence A000292 (Tetrahedral numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  5. ^ Sloane, N. J. A. (ed.). "Sequence A000931 (Padovan sequence)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  6. ^ Sloane, N. J. A. (ed.). "Sequence A003215 (Hex (or centered hexagonal) numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  7. ^ Sloane, N. J. A. (ed.). "Sequence A000330 (Square pyramidal numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  8. ^ a b Sloane, N. J. A. (ed.). "Sequence A000217 (Triangular numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  9. ^ Sloane, N. J. A. (ed.). "Sequence A005282 (Mian-Chowla sequence)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  10. ^ a b c d Sloane, N. J. A. (ed.). "Sequence A006753 (Smith numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  11. ^ a b Sloane, N. J. A. (ed.). "Sequence A016038 (Strictly non-palindromic numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  12. ^ Sloane, N. J. A. (ed.). "Sequence A001006 (Motzkin numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  13. ^ a b c Sloane, N. J. A. (ed.). "Sequence A005385 (Safe primes)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  14. ^ Sloane, N. J. A. (ed.). "Sequence A100827 (Highly cototient numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  15. ^ Sloane, N. J. A. (ed.). "Sequence A002182 (Highly composite numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  16. ^ a b Sloane, N. J. A. (ed.). "Sequence A036913 (Sparsely totient numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  17. ^ Sloane, N. J. A. (ed.). "Sequence A001844 (Centered square numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  18. ^ Sloane, N. J. A. (ed.). "Sequence A069099 (Centered heptagonal numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  19. ^ Sloane, N. J. A. (ed.). "Sequence A016754 (Odd squares: a(n) = (2n+1)^2. Also centered octagonal numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  20. ^ Sloane, N. J. A. (ed.). "Sequence A000032 (Lucas numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  21. ^ Sloane, N. J. A. (ed.). "Sequence A000326 (Pentagonal numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  22. ^ Sloane, N. J. A. (ed.). "Sequence A001608 (Perrin sequence)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  23. ^ Sloane, N. J. A. (ed.). "Sequence A001107 (10-gonal (or decagonal) numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  24. ^ Sloane, N. J. A. (ed.). "Sequence A005898 (Centered cube numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  25. ^ Sloane, N. J. A. (ed.). "Sequence A001106 (9-gonal (or enneagonal or nonagonal) numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  26. ^ Sloane, N. J. A. (ed.). "Sequence A005891 (Centered pentagonal numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  27. ^ Sloane, N. J. A. (ed.). "Sequence A007850 (Giuga numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  28. ^ Sloane, N. J. A. (ed.). "Sequence A000384 (Hexagonal numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  29. ^ Sloane, N. J. A. (ed.). "Sequence A014439 (Differences between two positive cubes in exactly 1 way.)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2019-08-18.
  30. ^ Sloane, N. J. A. (ed.). "Sequence A000110 (Bell or exponential numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  31. ^ Sloane, N. J. A. (ed.). "Sequence A319190 (Number of regular hypergraphs)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2019-08-18.
  32. ^ Sloane, N. J. A. (ed.). "Sequence A003261 (Woodall numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.