13580
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 32928
- Proper Divisor Sum (Aliquot Sum)
- 19348
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4608
- Möbius Function
- 0
- Radical
- 6790
- 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
- 37
- 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
- Expansion of e.g.f.: arcsinh(sech(x)*log(x+1))=x-1/2!*x^2-2/3!*x^3+6/4!*x^4+33/5!*x^5...at n=8A012874
- Pisot sequences E(6,8), P(6,8).at n=27A020716
- a(n) = n*(17*n - 1)/2.at n=40A022274
- Dying rabbits: a(n) = a(n-1) + a(n-2) - a(n-4).at n=33A023434
- a(n) = least number not of form [ (a^2+b^2)/n ].at n=28A036574
- a(n) = T(n,n-5), array T as in A055807.at n=18A055810
- Numbers n such that phi(reversal(n)) = reversal(phi(n)). Ignore leading 0's.at n=17A069282
- Positive integers k such that k!!! - 1 = A007661(k) - 1 is prime.at n=20A084438
- Matrix product of unsigned Lah-triangle |A008297(n,k)| and Stirling2-triangle A008277(n,k).at n=24A088814
- Least common multiple of all cycle sizes in range [A014137(n-1)..A014138(n-1)] of permutation A071655/A071656.at n=6A089415
- Double partial sums of (n * its dyadic valuation).at n=43A090889
- a(1) = greatest k such that H(k) - H(8) < H(8) - H(4); a(2) = greatest k such that H(k) - H(a(1)) < H(a(1)) - H(8), and for n > 2, a(n) = greatest k such that H(k) - H(a(n-1)) > H(a(n-1)) - H(a(n-2)), where H = harmonic number.at n=12A227804
- Number of length n+5 0..4 arrays with no six consecutive terms having five times any element equal to the sum of the remaining five.at n=0A249526
- T(n,k)=Number of length n+5 0..k arrays with no six consecutive terms having five times any element equal to the sum of the remaining five.at n=6A249530
- Number of length 1+5 0..n arrays with no six consecutive terms having five times any element equal to the sum of the remaining five.at n=3A249531
- Triangle read by rows: number of idempotents of rank k in partial Brauer monoid PB_n.at n=31A256039
- Triangular array read by rows, the matrix product of the unsigned Lah numbers and the Stirling set numbers, T(n,k) for n>=0 and 0<=k<=n.at n=32A256892
- a(n) = A001235(n) - floor(A001235(n)^(1/3))^3.at n=24A273555
- a(n) = 2*a(n-1) + 2*a(n-2) - 3*a(n-3), where a(0) = 2, a(1) = 4, a(2) = 8.at n=11A288309
- The number of partitions of [n] with exactly 2 blocks without peaks.at n=17A289692