13971
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 18632
- Proper Divisor Sum (Aliquot Sum)
- 4661
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9312
- Möbius Function
- 1
- Radical
- 13971
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- yes
- Squarefree Number
- yes
- 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
- no
- Odd
- yes
Appears in sequences
- Unexplained difference between two partition generating functions.at n=9A007329
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 39.at n=37A031537
- Expansion of 1 + Sum_{i>=1} (x^prime(i)/Product_{j=1..i} (1-x^j)).at n=50A095700
- Expansion of g.f.: (1-x)*(1+2*x)/((1+x)*(1-3*x+x^2)).at n=10A129905
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, -1, 1), (-1, 0, 1), (0, 1, -1), (1, 0, 1)}.at n=9A148797
- Parameters n for which the elliptic curve y^2=x^3-n has rank 4.at n=15A179137
- Number of independent sets of nodes in the generalized Petersen graph G(2n+1,2) (n>=1).at n=4A182077
- Number of ordered quintuples of distinct pairwise coprime positive integers with largest element n.at n=48A186976
- Triangle T(n, k) = Numbers of ways to place k points on a triangular grid of side n so that no three of them are vertices of an equilateral triangle with sides parallel to the grid. Triangle read by rows.at n=31A243211
- Number of ways to place 5 points on a triangular grid of side n, so that no three of them are vertices of an equilateral triangle with sides parallel to the grid.at n=3A243214
- Triangle read by rows in which each new term is the sum of its two largest neighbors in the structure.at n=34A278645
- a(n) = a(n-1) + a(n-3) + a(n-4), where a(0) = 2, a(1) = 0, a(2) = 1, a(3) = 1.at n=22A295684
- T(n,m) is the numerator of the resistance between two diametrically opposite nodes of a rectangular electric network of n*m quadratic cells in which all edges are replaced by one-ohm resistors, where T(n,m) is a triangle read by rows.at n=29A357113
- a(n) = number of subsets S of {1,2,...,n} having more than 2 elements such that (sum of least three elements of S) > max(S).at n=16A357289
- Index where prime(n) appears as a term in A379442.at n=46A379558
- Number of integer partitions of n with the same number of adjacent equal parts as adjacent unequal parts.at n=49A385574