15743
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 19488
- Proper Divisor Sum (Aliquot Sum)
- 3745
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12384
- Möbius Function
- -1
- Radical
- 15743
- Omega Function (Ω)
- 3
- 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
- 84
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- Expansion of 1/((1-x)(1-3x)(1-6x)(1-7x)).at n=4A021494
- a(n) = (d(n)-r(n))/2, where d = A026037 and r is the periodic sequence with fundamental period (1,0,0,1).at n=43A026038
- Least number beginning with prime(n) such that every concatenation is a prime.at n=36A090508
- a(n) = n*(n+1)*(3*n^2+n-1)/6.at n=13A103220
- a(0)=0, a(1)=1; thereafter a(n) = ceiling((3/2)^(n-3)*n*(n-1)).at n=14A120414
- Number of permutations of 5 copies of 1..n introduced in order 1..n with no element equal to another within a distance of 2.at n=3A190834
- Number of permutations of n copies of 1..4 introduced in order 1..4 with no element equal to another within a distance of 2.at n=4A190919
- Second elementary symmetric function of the first n terms of (1,1,2,2,3,3,4,4,...).at n=24A203246
- Number of n X 2 arrays of the minimum value of corresponding elements and their horizontal or diagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 n X 2 array.at n=20A220147
- a(n) = Sum_{k=0..3} binomial(6,k)*binomial(n,k).at n=17A247608
- Numbers n such that 4n + 1, 4n + 2 and 4n + 3 are not squarefree.at n=38A258332
- Odd numbers n such that the sum of the binary digits of n and n^2 both equal 12.at n=12A261593
- Decimal representation of the x-axis, from the origin to the right edge, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 377", based on the 5-celled von Neumann neighborhood.at n=15A281631
- Decimal representation of the x-axis, from the origin to the right edge, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 379", based on the 5-celled von Neumann neighborhood.at n=13A281635
- Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 581", based on the 5-celled von Neumann neighborhood.at n=13A289526
- Largest finite number of distinct words arising in Watanabe's tag system {00, 1011} applied to a binary word w, over all starting words w of length n.at n=34A291067
- Number of partitions of n into colored blocks of equal parts, such that all colors from a set of size three are used and the colors are introduced in increasing order.at n=19A327286
- a(n) is the total number of points (both boundary and interior points) in the n-th figure shown in A255011 (meaning the figure with 4n points on the perimeter), where the interior points are counted with multiplicity.at n=6A334698
- a(n) = Sum_{k=1..n} (-1)^(k+1) * floor(n/k)^3.at n=25A344721
- Table read by antidiagonals: Place k points in general position on each side of a regular n-gon and join every pair of the n*(k+1) boundary points by a chord; T(n,k) (n >= 3, k >= 0) gives number of vertices in the resulting planar graph.at n=29A367183