9020
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 21168
- Proper Divisor Sum (Aliquot Sum)
- 12148
- 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
- 3200
- Möbius Function
- 0
- Radical
- 4510
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 140
- 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
- a(n) = (n^3 + 2*n)/3.at n=30A006527
- Number of extreme points of the set of n X n symmetric doubly-stochastic matrices.at n=8A006847
- Triangle of Lehmer-Comtet numbers of the first kind.at n=58A008296
- s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n-k+1), where k = [ n/2 ], s = A001950 (upper Wythoff sequence).at n=23A025122
- a(n) = T(2n,n-2), T given by A026747.at n=5A026750
- Numbers in which 0,1,2,3,4,5 all occur in base 6.at n=23A031947
- Number of nonempty subsets of {1,2,...,n} in which exactly 1/4 of the elements are <= (n+1)/3.at n=16A048041
- Number of nonempty subsets of {1,2,...,n} in which exactly 1/4 of the elements are <= (n-4)/2.at n=16A048063
- Number of nonempty subsets of {1,2,...,n} in which exactly 1/4 of the elements are <= (n+2)/3.at n=16A048074
- Number of nonempty subsets of {1,2,...,n} in which exactly 1/4 of the elements are <= (n+3)/3.at n=16A048085
- Digitally balanced numbers in base 6: equal numbers of 0's, 1's, ..., 5's.at n=23A049357
- Denominators of column 2 of table described in A051714/A051715.at n=38A051719
- Denominators of column 2 of table described in A051714/A051715.at n=39A051719
- Number of multi-directed animals on the square lattice.at n=8A059713
- One half of A075178.at n=40A075179
- Boustrophedon transform (first version) of Fibonacci numbers 1, 1, 2, 3, 5, 8, ...at n=8A092073
- Slowest increasing sequence where the absolute difference between the last digit of a(n) and the first digit of a(n+1) equals 9.at n=14A101243
- a(n) = n*(n+7)*(n+8)/6.at n=33A111396
- Number of permutations of length n which avoid the patterns 1342, 2341, 4132; or avoid the patterns 2431, 3124, 4231.at n=8A116742
- Terms of A068563 that are not terms of A124240.at n=36A124241