12748
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 22316
- Proper Divisor Sum (Aliquot Sum)
- 9568
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6372
- Möbius Function
- 0
- Radical
- 6374
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 125
- 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) = a(n-1) + 2*a(n-2) + (-1)^n.at n=14A006904
- a(0)=1, a(n)=2^n+n-2*a(n-1).at n=14A082383
- Number of partitions of n in which every part occurs 1, 4, or 5 times. Also number of partitions of n in which every part is congruent to {1, 3, 4, 5, 7} mod 8.at n=50A100853
- Riordan array (1/sqrt(1-2*x-3*x^2), 1/sqrt(1-2*x-3*x^2) -1).at n=49A116392
- Number of nX3 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.at n=4A199642
- Number of nX5 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.at n=2A199644
- T(n,k)=Number of nXk 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.at n=23A199647
- T(n,k)=Number of nXk 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.at n=25A199647
- Numbers n such that 8^n + 3 is prime.at n=24A217354
- Number of permutations of length n whose powers all avoid the pattern 321.at n=11A326760
- a(n) is the number of tilings of the Aztec diamond of order n using dominoes and horizontal straight tetrominoes.at n=4A356523
- Number of regions formed inside a right triangle by the straight line segments mutually connecting all vertices and points on the two shorter edges whose positions on one edge equal the Farey series of order n while on the other they divide its length into n equal segments.at n=8A359975
- Array read by downward antidiagonals: A(n,k) = A(n-1,k+1) + Sum_{j=0..k} binomial(k+1,j)*A(n-1,j)*A(k-j,0) with A(0,k) = 1.at n=23A392058