13940
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 31752
- Proper Divisor Sum (Aliquot Sum)
- 17812
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5120
- Möbius Function
- 0
- Radical
- 6970
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 4
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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 182
- 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
- dot product (n,n-1,...2,1).(3,4,...,n,1,2).at n=38A026054
- Numbers k whose decimal representation, read as a base-18 value and divided by k, yields an integer.at n=25A032567
- a(n) = Sum_{k=1..n} lcm(n,k).at n=33A051193
- Number of 4-block ordered tricoverings of an unlabeled n-set.at n=39A060488
- Column 1 of triangle A091615.at n=12A091622
- Triangle read by rows: T(n,k) is the number of Motzkin paths of length n with k peaks (n>=0, 0<=k<=floor(n/2)).at n=50A097860
- a(n) = (p^2 - 1) / 12, where p is the n-th prime of the form 4*k+1.at n=38A109255
- Number of (1,0) steps in all peakless Motzkin paths of length n (can be easily translated into RNA secondary structure terminology).at n=11A110236
- Let n = a_1a_2...a_k, where the a_i are digits. a(n) = least multiple of n of the type b_1a_1b_2a_2...a_kb_{k+1}, obtained by inserting single digits b_i in the gaps and both ends; 0 if no such number exists.at n=33A110735
- Numbers k such that k^2 divides 21^k-1.at n=33A128401
- Numbers k such that k^3 divides 3^(k^2) - 1.at n=36A129211
- Least common multiple of prime(n)-3 and prime(n)+3.at n=38A166011
- (A178476(n)-3)/9.at n=15A178486
- 17 times triangular numbers.at n=40A195037
- a(n) = Sum_{k=floor(n/4)..R} C(k, m*k - (-1)^n*(R - k)) * C(k + 1, m*(k + 2) - (-1)^n*(R - k + 1)) where m = (n + 1) mod 2 and R = (n + m - 3)/2 for n > 0 and a(0) = 1.at n=25A202411
- Number of (w,x,y,z) with all terms in {1,...,n} and w<x>=y<=z.at n=16A212415
- Number of simple unlabeled graphs on n nodes with exactly 7 connected components that are trees or cycles.at n=13A215987
- Number of binary arrays indicating the locations of trailing edge maxima of a random length-n 0..5 array extended with zeros and convolved with 1,2,1.at n=19A222124
- Number of (n+2) X (1+2) 0..1 arrays with no 3 x 3 subblock diagonal sum 0 or 1 and no antidiagonal sum 0 or 1 and no row sum 0 or 1 and no column sum 0 or 1.at n=8A255020
- T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with no 3x3 subblock diagonal sum 0 or 1 and no antidiagonal sum 0 or 1 and no row sum 0 or 1 and no column sum 0 or 1.at n=36A255027