13161
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 18144
- Proper Divisor Sum (Aliquot Sum)
- 4983
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8480
- Möbius Function
- -1
- Radical
- 13161
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 200
- 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
- a(n) = (n+1)*(n^2 +8*n +6)/6. Number of n-dimensional partitions of 4. Number of terms in 4th derivative of a function composed with itself n times.at n=40A008778
- Expansion of 1/((1-4x)(1-5x)(1-7x)).at n=4A018209
- Number of polyominoes with n cells, symmetric about two orthogonal axes.at n=32A056877
- Number of balanced primes (A090403) less than 10^n.at n=5A096711
- Odd winning positions in Fibonacci nim.at n=31A120904
- Number of length 3+2 0..n arrays with every three consecutive terms having the sum of some two elements equal to twice the third.at n=43A248436
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 485", based on the 5-celled von Neumann neighborhood.at n=25A272504
- a(n) is the number of triangles (up to congruence) with integer coordinates that have perimeter strictly less than n.at n=37A298121
- Number of polyominoes of n cells with both horizontal and vertical symmetries, for which the 180-degree rotational symmetry has an axis that coincides with the center of a square, but without 90-degree rotational symmetry.at n=32A351190
- a(n) = Sum_{d|n} (n/d)^(n-n/d) * binomial(d+n-2,n-1).at n=7A363667
- One-third of the total number of edges formed after n points have been placed in general position on each edge of a triangle (as in A365929).at n=10A389626