12399
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 16536
- Proper Divisor Sum (Aliquot Sum)
- 4137
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8264
- Möbius Function
- 1
- Radical
- 12399
- Omega Function (Ω)
- 2
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 262
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- 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 proper factorizations of p1^n*p2^5, where p1 and p2 are distinct primes.at n=13A031128
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 37.at n=40A031535
- Expansion of g.f. x^3/(1 - 2*x + x^3 - x^4).at n=15A059633
- Self-convolution equals A112565.at n=8A112567
- Least k such that the Collatz (3x+1) iteration starting with k has "dropping time" A122437(n).at n=47A122442
- Triangle, read by rows, of coefficients of q^(nk) in the q-analog of the even double factorials: T(n,k) = [q^(nk)] Product_{j=1..n} (1-q^(2j))/(1-q) for n>0, with T(0,0)=1.at n=30A128596
- Triangle, read by rows, of coefficients of q^(nk) in the q-analog of the even double factorials: T(n,k) = [q^(nk)] Product_{j=1..n} (1-q^(2j))/(1-q) for n>0, with T(0,0)=1.at n=33A128596
- Column 2 of triangle A128596; a(n) = coefficient of q^(2n+4) in the q-analog of the even double factorials (2n+4)!! for n>=0.at n=5A128597
- Smallest precursor of n-th cycle in the "Recurring Digital Invariant Variant" problem.at n=27A151543
- a(n) = 400*n - 1.at n=30A158317
- Number of reduced words of length n in the Weyl group B_7.at n=14A161716
- Number of reduced words of length n in the Weyl group B_7.at n=35A161716
- Fibonacci sequence beginning 9, 7.at n=16A190995
- Number of nX4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,3,1,1,0 for x=0,1,2,3,4.at n=5A197346
- Number of n X 6 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,3,1,1,0 for x=0,1,2,3,4.at n=3A197348
- T(n,k)=Number of nXk 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 3,3,1,1,0 for x=0,1,2,3,4.at n=39A197350
- T(n,k)=Number of nXk 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 3,3,1,1,0 for x=0,1,2,3,4.at n=41A197350
- a(0) = 1, a(n) = Sum_{k=1..n} a(n-k)*ceiling(sin(k)).at n=16A265826