13128
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 32880
- Proper Divisor Sum (Aliquot Sum)
- 19752
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4368
- Möbius Function
- 0
- Radical
- 3282
- 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
- yes
- 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
- Numbers that are the sum of 8 nonzero 8th powers.at n=17A003386
- Triangle T(n,k) read by rows, defined by T(n,k) = (n-k)*T(n-1,k)+Sum(k=1..n, T(n-1,k)); T(1,1) = 1, T(1,k)= 0 if k >1.at n=22A089225
- a(n) = smallest value of k such that n*k^(1/n) >= (n+1)*k^(1/(n+1)).at n=8A120369
- Expansion of f(q)*f(q^7)/(f(-q)*f(-q^7)) in powers of q where f() is a Ramanujan theta function.at n=35A123862
- Equals one maps: number of nX2 binary arrays indicating the locations of corresponding elements equal to exactly one of their king-move neighbors in a random 0..2 nX2 array.at n=6A220964
- T(n,k)=Equals one maps: number of nXk binary arrays indicating the locations of corresponding elements equal to exactly one of their king-move neighbors in a random 0..2 nXk array.at n=29A220967
- T(n,k)=Equals one maps: number of nXk binary arrays indicating the locations of corresponding elements equal to exactly one of their king-move neighbors in a random 0..2 nXk array.at n=34A220967
- Numbers n such that m + (sum of digits in base-3 representation of m) = n has exactly four solutions.at n=46A230856
- Number of n X 2 0..4 arrays with no element equal to the sum of elements to its left or the sum of elements above it, modulo 5.at n=3A239188
- Number of nX4 0..4 arrays with no element equal to the sum of elements to its left or the sum of elements above it, modulo 5.at n=1A239190
- T(n,k)=Number of nXk 0..4 arrays with no element equal to the sum of elements to its left or the sum of the elements above it, modulo 5.at n=11A239194
- T(n,k)=Number of nXk 0..4 arrays with no element equal to the sum of elements to its left or the sum of the elements above it, modulo 5.at n=13A239194
- Partial sums of A263614 starting at n=2.at n=35A263615
- a(n) is the number of equivalence classes of simple, open polygonal chains consisting of two segments and with all three vertices on the lattice points of an n X n grid.at n=12A272053
- Expansion of Product_{k>=1} (1 + x^prime(k))^prime(k).at n=29A291647
- Birooted graphs: number of unlabeled graphs with n nodes rooted at 2 indistinguishable roots.at n=6A303829
- Number of nX5 0..1 arrays with every element unequal to 1, 2, 4, 5 or 8 king-move adjacent elements, with upper left element zero.at n=6A305449
- Number of nX7 0..1 arrays with every element unequal to 1, 2, 4, 5 or 8 king-move adjacent elements, with upper left element zero.at n=4A305451
- T(n,k)=Number of nXk 0..1 arrays with every element unequal to 1, 2, 4, 5 or 8 king-move adjacent elements, with upper left element zero.at n=59A305452
- T(n,k)=Number of nXk 0..1 arrays with every element unequal to 1, 2, 4, 5 or 8 king-move adjacent elements, with upper left element zero.at n=61A305452