13980
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
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 39312
- Proper Divisor Sum (Aliquot Sum)
- 25332
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3712
- Möbius Function
- 0
- Radical
- 6990
- 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
- 58
- 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) = 10000*log_10(n) rounded up.at n=24A004230
- Number of ways in which n identical balls can be distributed among 4 boxes in a row such that each pair of adjacent boxes contains at least 4 balls.at n=35A005337
- "BIJ" (reversible, indistinct, labeled) transform of 1,3,5,7...at n=6A032115
- Number of ways to place 4 nonattacking queens on a 4 X n board.at n=15A061990
- Trisection of A007294.at n=36A073472
- Number of systems with n elements with one binary operation satisfying the equation B(AB)=A (semisymmetric quasigroups). Isomorphic systems and systems differing by a transposition have been omitted.at n=8A076018
- Sum of terms in n-th row of A081491.at n=14A081492
- Non-palindromic n and its digit reversal have the same sum of prime factors (with repetition).at n=32A085607
- a(n) is the smallest x for which the following quotient is an integer: (sigma(x) + ... + sigma(x+n-1))/sigma(x+(x+1)+ ... + (x+n-1)), i.e., sum(sigma(j))/sigma(sum(j)) for n terms summed up was integer.at n=4A091293
- Triangle read by rows: T(n,k) is the number of k-matchings of the corona L'(n) of the ladder graph L(n)=P_2 X P_n. and the complete graph K(1); in other words, L'(n) is the graph constructed from L(n) by adding for each vertex v a new vertex v' and the edge vv'.at n=41A102435
- Triangle read by rows: T(n,k) is the number of k-matchings of the corona L'(n) of the ladder graph L(n)=P_2 X P_n. and the complete graph K(1); in other words, L'(n) is the graph constructed from L(n) by adding for each vertex v a new vertex v' and the edge vv'.at n=43A102435
- Number of linear arrangements of n blue, n red and n green items such that first and last elements have the same color but there are no adjacent items of the same color.at n=5A110711
- The following triangle is based on Pascal's triangle. The r-th term of the n-th row is sum of C(n,r) successive integers so that the sum of all the terms of the row is (2^n)*(2^n+1)/2, the 2^n -th triangular number. Sequence contains the triangle read by rows.at n=58A112358
- a(n) = Sum_{k=0..n} (n+k+3)!/((n-k)!*k!*2^k).at n=3A144514
- 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), (1, 1, -1), (1, 1, 0)}.at n=7A150826
- 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), (0, 1, -1), (0, 1, 0), (0, 1, 1), (1, 0, 0)}.at n=7A151073
- a(n) = 1000*n - 20.at n=13A157515
- a(n) = Fibonacci(n)*A109064(n) for n>=1 with a(0)=1.at n=13A205882
- Triangular array read by rows. T(n,k) is the number of functions f:{1,2,...,n}->{1,2,...,n} that have exactly k recurrent elements whose preimage contains only one element, n>=0, 0<=k<=n.at n=22A220234
- Number of length n+3 0..7 arrays with no consecutive four elements summing to more than 2*7.at n=1A241963