12204
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 9
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 31920
- Proper Divisor Sum (Aliquot Sum)
- 19716
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4032
- Möbius Function
- 0
- Radical
- 678
- Omega Function (Ω)
- 6
- Little Omega Function (ω)
- 3
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
- 156
- 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) = prime(n)*prime(n+1) - prime(n+1).at n=28A037167
- a(n) = T(n, n-5), array T as in A055818.at n=11A055822
- McKay-Thompson series of class 24F for Monster.at n=26A058576
- McKay-Thompson series of class 24d for Monster.at n=52A058587
- Numbers k such that sigma(k) = 2*usigma(k).at n=35A063880
- Numbers k such that 2^k + 3^(k-1) is prime.at n=46A082400
- Coefficients of replicable function number 24e.at n=52A112163
- Triangle read by rows: T(n,k) is the number of deco polyominoes of height n and having k 2-cell columns starting at level 0 (n >= 1; 0 <= k <= n-1).at n=29A121634
- a(n) = n * (n+1)^2 * (3*n^2 + 4*n + 2) / 12.at n=8A132122
- Number of reduced words of length n in Coxeter group on 3 generators S_i with relations (S_i)^2 = (S_i S_j)^10 = I.at n=13A165745
- Triangle read by rows: T(n,k) is the number of weighted lattice paths in L_n having k (1,0)-steps of weight 2 at level 0. The members of L_n are paths of weight n that start at (0,0) , end on the horizontal axis and whose steps are of the following four kinds: an (1,0)-step with weight 1, an (1,0)-step with weight 2, a (1,1)-step with weight 2, and a (1,-1)-step with weight 1. The weight of a path is the sum of the weights of its steps.at n=50A182891
- Number of length 6 nonnegative integer arrays starting and ending with 0 with adjacent elements unequal but differing by no more than n.at n=8A205343
- Numbers which do not reach zero under either of the iterations: x -> floor(sqrt(x)) * (x - floor(sqrt(x))^2) or y -> ceiling(sqrt(y)) * (ceiling(sqrt(y))^2 - y).at n=10A219963
- Numbers that form a Pythagorean 5-tuple with their first three arithmetic derivatives.at n=4A249105
- Denominators of r-Egyptian fraction expansion for (1/2)^(1/3), where r(k) = 1/(k+1).at n=4A270591
- Indices of primes in A266891.at n=20A304210
- a(n) is the first even number k such that there are exactly n pairs (p,q) where p and q are prime, p<=q, p+q = k, and p+A001414(k) and q+A001414(k) are also prime.at n=49A357816