8049
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 10736
- Proper Divisor Sum (Aliquot Sum)
- 2687
- 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
- 5364
- Möbius Function
- 1
- Radical
- 8049
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 70
- 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
- a(n) = floor(n*phi^12), where phi is the golden ratio, A001622.at n=25A004927
- a(n) = floor( n*(n-1)*(n-2)/23 ).at n=58A011905
- Expansion of Product_{m>=1} 1/(1 + m*q^m).at n=26A022693
- Numbers whose base-5 representation contains exactly two 2's and three 4's.at n=32A045288
- Number of connected planar graphs with n edges.at n=11A046091
- Expansion of (1-x)/(1-x-3*x^2).at n=12A052533
- Fundamental discriminants of real quadratic number fields with class number 5.at n=36A094614
- a(0)=1, a(1)=3, a(n) = 7*a(n-1) - 9*a(n-2) for n > 1.at n=6A165310
- a(n) = 2^n - n*(n-2).at n=13A176776
- Numbers k such that 9*k! + 1 is prime.at n=22A180626
- Number of subsets of {1..n} (including empty set) such that the pairwise GCDs of elements are not distinct.at n=23A196720
- [s(k)-s(j)]/9, where the pairs (k,j) are given by A205872 and A205873, and s(k) denotes the (k+1)-st Fibonacci number.at n=25A205875
- Number of n-bead necklaces labeled with numbers -1..1 allowing reversal, with sum zero and first differences in -1..1.at n=16A209025
- Triangle of coefficients of polynomials u(n,x) jointly generated with A210756; see the Formula section.at n=43A210755
- 7^n mod 10000.at n=21A216130
- Number of compositions [p(1), p(2), ..., p(k)] of n such that p(j) != p(j-2).at n=17A224958
- Semiprimes whose reversal + 1 is a square.at n=13A245362
- G.f. satisfies: A(x) = exp( Sum_{n>=1} [Sum_{k=0..3*n} T(n,k)^2 * x^k] / A(x)^n * x^n/n ) where T(n,k) equals the coefficient of x^k in (1+x+x^2+x^3)^n.at n=16A248876
- Number of (n+1) X (7+1) 0..2 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction.at n=1A250811
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction.at n=29A250812