13156
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 28224
- Proper Divisor Sum (Aliquot Sum)
- 15068
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5280
- Möbius Function
- 0
- Radical
- 6578
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 138
- 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) = floor(binomial(n,5)/5).at n=26A011851
- a(n) = [ a(n-1)/a(1) ] + [ a(n-3)/a(3) ] + [ a(n-5)/a(5) ] + ..., for n >= 3.at n=31A022866
- Numerator of n*(n-3)*(3*n^2-6*n+2)/(3*(n-1)*(n-2)).at n=8A023417
- Total number of vertices in all loopless rooted planar maps with n edges.at n=6A027836
- Expansion of 1/((1-x)^4*(1-x^2)^2).at n=19A028346
- Number of 3 X n binary matrices such that any 2 rows have a common 1, up to column permutations.at n=10A052387
- Numbers n such that sum of squares of even digits of n equals sum of squares of odd digits of n.at n=11A076164
- Array A(x,y) giving the position of the y-th x in A007001 listed by rising antidiagonals.at n=57A085180
- a(n) = n^3 + 114 * n.at n=21A122562
- Numbers k such that k^2 divides 21^k-1.at n=31A128401
- a(n) = (n-1)*(n+4)*(n+6)/6 for n > 1, a(1)=1.at n=39A137742
- Numbers n such that n^3 can be represented as sum of (at least two) consecutive squares.at n=6A163390
- Sequence defined by the recurrence formula a(n+1) = sum(a(p)*a(n-p)+k,p=0..n)+l for n>=1, with here a(0)=1, a(1)=1, k=-2 and l=0.at n=10A177111
- Numbers of ways in which a unit disc can be dissected into 6n curvilinear triangles, at least one of which does not contain the center.at n=25A193362
- Numbers k such that the sum of the divisors of k and the sum of the distinct prime divisors of k are both a square.at n=18A194196
- Triangle of coefficients of polynomials v(n,x) jointly generated with A208753; see the Formula section.at n=51A208754
- Integers m such that m^3 is the sum of two or more consecutive integer squares.at n=17A212018
- Number of (w,x,y,z) with all terms in {1,...,n} and w<|x-y|+|y-z|.at n=25A212692
- Number of (w,x,y) with all terms in {0,...,n} and n/2 < w+x+y <= n.at n=43A212977
- Antidiagonal sums of the convolution array A213778.at n=21A213780