13661
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
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 14400
- Proper Divisor Sum (Aliquot Sum)
- 739
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12924
- Möbius Function
- 1
- Radical
- 13661
- 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
- 151
- 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
- Numerators of continued fraction convergents to sqrt(359).at n=5A041680
- Numbers k such that 2^k + 3^(k-1) is prime.at n=48A082400
- Start with 1 and repeatedly reverse the digits and add 55 to get the next term.at n=34A118161
- Number of ON cells at n-th stage of three-dimensional version of the cellular automaton A160117 using cubes.at n=15A160379
- Number of lattice paths from (0,0) to (n,n) consisting of steps U=(1,1), H=(1,0) and S=(0,1) such that the first step leaving the diagonal (if any) is an H step and the last step joining the diagonal (if any) is a S step.at n=7A226995
- One-half of the x member of the positive proper fundamental solution (x = x2(n), y = y2(n)) of the second class for the Pell equation x^2 - D(n)*y^2 = +8 for even D(n) = A264354(n).at n=36A264438
- Numbers whose sum of divisors is equal to the product of the number of divisors of their k first powers, for some k.at n=30A283758
- Decimal representation of the x-axis, from the left edge to the origin, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 934", based on the 5-celled von Neumann neighborhood.at n=13A284425
- Expansion of Sum_{i>=1} mu(i)^2*x^i/(1 - x^i) * Product_{j>=i} 1/(1 - mu(j)^2*x^j), where mu() is the Moebius function (A008683).at n=31A284829
- Number of joining pairs of integer partitions of n.at n=25A318915
- Number of tilings of a 5 X n rectangle using n pentominoes of shapes T, W, I, X.at n=25A372221
- a(n) = Sum_{k=0..n} (-1)^k * binomial(3*n+2*k+1,n-k).at n=6A390544