12788
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 23520
- Proper Divisor Sum (Aliquot Sum)
- 10732
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6072
- Möbius Function
- 0
- Radical
- 6394
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 3
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 76
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- a(n) = 10000*log_10(n) rounded to the nearest integer.at n=18A004229
- a(n) = 10000*log_10(n) rounded up.at n=18A004230
- Numerators of continued fraction convergents to sqrt(997).at n=9A042930
- Largest member of the n-th row of the triangular triangle (A093445).at n=39A093446
- In chess, the number of "at home" dual-free proof games in n plies.at n=15A102784
- a(0) = 0, a(1) = a(2) = 1, a(3) = 2, a(4) = 4, a(5) = 8, for n>4: a(n+1) = SORT[ a(n) + a(n-1) + a(n-2) + a(n-3) + a(n-4) + a(n-5)], where SORT places digits in ascending order and deletes 0's.at n=39A108566
- a(n) = floor((Pi^2/6)^n).at n=19A125892
- a(n) = first term that can be reduced in n steps via repeated interpretation of a(n) as a base b+1 number where b is the largest digit of a(n), such that b is always 8 so that each interpretation is base 9. Terms already fully reduced (i.e., single digits) are excluded.at n=5A141842
- Expansion of Product_{k >= 0} (1 + A147954(k)*x^k).at n=30A147955
- a(n) = 441*n - 1.at n=28A158319
- 3-comma numbers: n occurs in the sequence S[k+1]=S[k]+10*last_digit(S[k-1])+first_digit(S[k]) for three different splittings n=concat(S[0],S[1]).at n=9A166513
- Half the number of n X n symmetric binary matrices with no element unequal to a strict majority of its king- and knight-move neighbors.at n=11A190659
- Number of 3Xn 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically.at n=8A207026
- Number of compositions of n having exactly ten fixed points.at n=13A240745
- First n elements of the Kolakoski sequence read as a ternary number.at n=9A248875
- Expansion of Product_{k>=0} 1/(1 - x^(3*k+1))^2.at n=39A261616
- a(n) = (A002703(n)+2)/2.at n=17A262569
- Number of triangular number parts in all partitions of n.at n=26A263235
- The number of partitions of n which represent Chomp positions with Sprague-Grundy value 2.at n=53A284688
- Number of nX3 0..1 arrays with every element equal to 0, 1, 3 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=11A302630