1183
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 1464
- Proper Divisor Sum (Aliquot Sum)
- 281
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 936
- Möbius Function
- 0
- Radical
- 91
- Omega Function (Ω)
- 3
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 88
- 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
- no
- Odd
- yes
Appears in sequences
- Number of stacks, or planar partitions of n; also weakly unimodal compositions of n.at n=14A001523
- Pentagonal pyramidal numbers: a(n) = n^2*(n+1)/2.at n=13A002411
- Number of perfect matchings (or domino tilings) in P_5 X P_2n.at n=3A003775
- a(n) = binomial(2*n-2,n-1)/n - 2^(n-1) + n.at n=8A004303
- Representation degeneracies for boson strings.at n=23A005292
- Indices of primes where largest gap occurs.at n=10A005669
- Coordination sequence T4 for Zeolite Code NES.at n=22A008208
- Expansion of g.f.: x^4/((1-x)*(1-x^2)^2*(1-x^3)).at n=44A008763
- Expansion of (1+x^4)/((1-x)*(1-x^2)*(1-x^3)*(1-x^4)).at n=41A008765
- Start with 1, apply 1->12, 21->21, 22->21, 2->2 (for final 2); a(n) = length of n-th term.at n=21A013950
- Odd pentagonal pyramidal numbers.at n=3A015223
- Pseudoprimes to base 22.at n=12A020150
- Pseudoprimes to base 23.at n=19A020151
- Strong pseudoprimes to base 22.at n=4A020248
- Least k such that k and 4k are anagrams in base n (written in base 10).at n=17A023096
- a(n) is least k such that k and 7k are anagrams in base n (written in base 10).at n=14A023099
- Convolution of natural numbers with A014306.at n=51A023544
- a(n) = [ C(2n,n)/2^(n+2) ].at n=15A024505
- a(n) = Sum_{k=1..n} floor((n/k) * floor((n/k) * floor(n/k))).at n=9A024922
- Coordination sequence T3 for Zeolite Code MWW.at n=23A024988