10980
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 36
- Divisor Sum
- 33852
- Proper Divisor Sum (Aliquot Sum)
- 22872
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 2880
- Möbius Function
- 0
- Radical
- 1830
- Omega Function (Ω)
- 6
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 42
- 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 1/((1-x)^2*Product_{k>=1} (1-x^k)).at n=20A014153
- Number of ways to color cells of an n X n square with 2 colors so that no subsquare of side > 1 has all corners same color.at n=4A018803
- Fibonacci sequence beginning 0, 18.at n=15A022352
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (natural numbers), t = A000201 (lower Wythoff sequence).at n=41A024863
- Dirichlet convolution of d(n) (number of divisors) with Fibonacci numbers.at n=20A034772
- Numbers k such that k + the reversal of k is a square.at n=37A061230
- Number of hexagonal regions in regular n-gon with all diagonals drawn.at n=39A067153
- Numbers occurring twice in A068627.at n=15A068628
- Row sums in A083175.at n=17A083175
- Smallest number having exactly n divisors that are not greater than the number's greatest prime factor.at n=16A087134
- a(n) = 4*n^3 + 4.at n=14A100214
- Second row of array in A101385.at n=14A101644
- Expansion of 1/((x-1)*(x+1)*(x^2+x+1)*(x^2+x-1)*(x^2-x+1)*(x^2+1)*(x^4-x^2+1)).at n=20A109609
- Positive integers i for which A112049(i) == 7.at n=27A112067
- The difference between the largest part and the smallest part summed over all those partitions of n in which every integer from the smallest part to the largest part occurs.at n=45A117471
- Numbers n that raised to the powers from 1 to k (with k>=1) are multiple of the sum of their digits (n raised to k+1 must not be a multiple). Case k=8.at n=20A135193
- a(n) = 1000*n - 20.at n=10A157515
- Triangle T(m,n) read by rows: T(m,n) = Sum_{k=1..n} StirlingS2(m, n) * StirlingS2(m, k).at n=17A167128
- Wiener index of the n-web graph.at n=19A180576
- a(n) = Sum_{i=0..n} Sum_{j=0..n} (i XOR j), where XOR is the binary logical exclusive-or operator.at n=26A224923