5242
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7866
- Proper Divisor Sum (Aliquot Sum)
- 2624
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 2620
- Möbius Function
- 1
- Radical
- 5242
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 147
- Smith Number
- yes
- 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
- yes
- Odd
- no
Appears in sequences
- Boustrophedon transform (first version) of Fibonacci numbers 0,1,1,2,3,5,...at n=8A000687
- Triangle read by rows: T(n,k) = number of permutations of length n with exactly k rising or falling successions, for n >= 1, 0 <= k <= n-1.at n=28A001100
- Hertzsprung's problem: ways to arrange n non-attacking kings on an n X n board, with 1 in each row and column. Also number of permutations of length n without rising or falling successions.at n=8A002464
- Coordination sequence T2 for Zeolite Code NON.at n=44A008213
- Numbers k giving rise to prime quadruples (30k+11, 30k+13, 30k+17, 30k+19).at n=44A014561
- Numbers k such that the continued fraction for sqrt(k) has period 33.at n=17A020372
- n written in fractional base 8/5.at n=34A024647
- a(n) = Sum{T(i,j)}, 0<=i<=n, 0<=j<=n, T given by A026681.at n=10A026690
- a(n) = T(2n-1,n-1), T given by A026758. Also T(2n+1,n+1), T given by A026747.at n=6A026762
- a(n) = T(n, floor(n/2)), T given by A026758.at n=13A026764
- Greatest number in row n of array T given by A026758.at n=13A027230
- Number of distinct products ijk with 1 <= i,j,k <= n.at n=42A027425
- Starting index of a string of 4 or more consecutive equal digits in decimal expansion of Pi.at n=6A049516
- Starting index of a string of exactly 4 consecutive equal digits in decimal expansion of Pi.at n=3A049520
- Nearest integer to n^tan(n).at n=42A054672
- Numbers k such that sigma(reverse(k)) = sigma(reverse(k-1)) + sigma(reverse(k-2)).at n=9A069970
- Starting positions of strings of three 7's in the decimal expansion of Pi.at n=4A083631
- a(1)=0, a(2)=1, a(n)=A000217(a(n-1)) + A000217(a(n-2)).at n=7A091957
- Counts where both the odd composites (starting from 1) 1 mod 4 and 3 mod 4 are equal.at n=2A093182
- Permanent of the (0,1)-matrix with ij-th entry equal to zero iff (i=1,j=1),(i=1,j=2),(i=1,j=3),(i=2,j=3),(i=3,j=3),... In other words, the ij-th entry of the matrix is zero iff it is on the path which start from the entry (i=1,j=1) and moves in the matrix alternating 3 steps to the right to 3 steps down.at n=8A098926