13736
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 5
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 27540
- Proper Divisor Sum (Aliquot Sum)
- 13804
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 6400
- Möbius Function
- 0
- Radical
- 3434
- Omega Function (Ω)
- 5
- 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
- 107
- 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
- One half of the number of permutations of [n] such that the differences have three runs with the same signs.at n=6A000352
- Triangle T(n,k) = P(n,k)/2, n >= 2, 1 <= k < n, of one-half of number of permutations of 1..n such that the differences have k runs with the same signs.at n=38A008970
- Even octagonal numbers: a(n) = 4*n*(3*n-1).at n=34A014642
- a(n) = Sum_{ d divides n } q(d), where q(d) = A000009 = number of partitions of d into distinct parts.at n=61A047966
- Composite numbers n such that sigma(n)+12 = sigma(n+12).at n=8A054902
- Numbers n such that n and 2^n end with the same three digits.at n=13A067866
- Generalized Catalan numbers 2*x*A(x)^2 -A(x) +1 -x =0.at n=7A068764
- Numbers k divisible by their abundance sigma(k) - 2*k.at n=50A097498
- Number of permutations of floor(i*8/3), i=0..n-1, with all sums of 2 through 4 adjacent terms respectively unique.at n=7A147939
- Number of permutations of floor(i*8/3), i=0..n-1, with all sums of 2 through 5 adjacent terms respectively unique.at n=7A147948
- Abundant numbers n such that n/(sigma(n)-2n) is an integer.at n=24A153501
- Consider the base-5 Kaprekar map n->K(n) defined in A165032. Sequence gives numbers belonging to cycles, including fixed points.at n=13A165037
- Consider the base-5 Kaprekar map n->K(n) defined in A165032. Sequence gives numbers belonging to cycles of length greater than 1.at n=10A165039
- a(n) = n*(n+1)*(20*n-17)/6.at n=16A172117
- Index of first occurrence of 2n in A031883, or 0 if 2n never occurs in A031883 = first differences of lucky numbers A000959.at n=46A181558
- Abundant numbers n for which the abundance d = sigma(n) - 2*n is a proper divisor, that is, 0 < d < n and d | n.at n=22A181595
- a(n) = 8*n^2 + 7*n + 1.at n=41A194268
- Symmetric triangle T, read by rows, where the matrix product of T and T transpose yields a square array which, when read by antidiagonals, equals this triangle read by rows.at n=60A194949
- Central terms of triangle A194949 = sums of squares of terms in rows of triangle A194949.at n=5A194951
- Number of (w,x,y,z) with all terms in {1,...,n} and min{|w-x|,|w-y|}=min{|x-y|,|x-z|}.at n=20A212579