4950
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- yes
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 36
- Divisor Sum
- 14508
- Proper Divisor Sum (Aliquot Sum)
- 9558
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 1200
- Möbius Function
- 0
- Radical
- 330
- 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
- yes
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- yes
- 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
- 72
- 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
- Triangle of Narayana numbers T(n,k) = C(n-1,k-1)*C(n,k-1)/k with 1 <= k <= n, read by rows. Also called the Catalan triangle.at n=62A001263
- Triangle of Narayana numbers T(n,k) = C(n-1,k-1)*C(n,k-1)/k with 1 <= k <= n, read by rows. Also called the Catalan triangle.at n=58A001263
- Eighth column of quadrinomial coefficients.at n=6A001919
- Denominator of Sum_{i+j+k=n; i,j,k > 0} 1/(i*j*k).at n=11A002546
- Number of n-bead bracelets (turnover necklaces) with 8 red beads and n-8 black beads.at n=13A005514
- Number of tree-rooted planar maps with 3 faces and n vertices and no isthmuses.at n=8A006470
- a(n) = binomial(n,3)*binomial(n-1,3)/4.at n=7A006542
- Kaprekar numbers: positive numbers n such that n = q+r and n^2 = q*10^m+r, for some m >= 1, q >= 0 and 0 <= r < 10^m, with n != 10^a, a >= 1.at n=11A006886
- Theta series of laminated lattice LAMBDA_10.at n=4A006909
- Coordination sequence T2 for Zeolite Code MTN.at n=42A008187
- Sum along upward diagonal of Pascal triangle from center.at n=21A010757
- a(n) = 2*n*(4*n - 1).at n=25A014635
- Numbers k such that phi(k) + 9 | sigma(k).at n=5A015800
- Binomial coefficients C(n,98).at n=2A017762
- Binomial coefficients C(100,n).at n=2A017816
- a(n) = dot_product(1,2,...,n)*(3,4,...,n,1,2).at n=22A026037
- a(n) = T(n, 2*n-7), T given by A027926.at n=10A027930
- a(n) = T(2n,n+3), T given by A027948.at n=4A027951
- a(n) = greatest number in row n of array T given by A027948.at n=14A027957
- 5 times triangular numbers: a(n) = 5*n*(n+1)/2.at n=44A028895