7860
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
- 24
- Divisor Sum
- 22176
- Proper Divisor Sum (Aliquot Sum)
- 14316
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 2080
- Möbius Function
- 0
- Radical
- 3930
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 4
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
- 145
- 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) + a(n - 1 - number of even terms so far).at n=40A006336
- a(n) = floor(exp(4/9)*n!).at n=6A030955
- 20-gonal (or icosagonal) numbers: a(n) = n*(9*n-8).at n=30A051872
- Number of nonisomorphic n-state automata with binary inputs and outputs.at n=2A054052
- Number of asymmetric n X n binary matrices under action of dihedral group of the square D_4.at n=4A054407
- 3rd level triangle related to Eulerian numbers and binomial transforms (A062253 is second level, triangle of Eulerian numbers is first level and triangle with Z(0,0)=1 and Z(n,k)=0 otherwise is 0th level).at n=33A062254
- Expansion of 1/((1-x)*(1+x+2*x^2-2*x^3)).at n=19A077910
- a(n) = T(n^3) - T(n), where T() are the triangular numbers (A000217).at n=5A085742
- G.f.: (1+x^2)^2*(x^4-6*x^3+1)/(x^2-1)^4.at n=36A115046
- Icosagonal numbers divisible by 20.at n=6A117798
- a(n) = 14 + floor((1 + Sum_{j=1..n-1} a(j))/3).at n=22A120158
- Number of wide partitions whose first part is of size n.at n=7A133787
- Number of permutations of 2 copies of 1..n with all adjacent differences <= 1 in absolute value.at n=15A177282
- Number of 2 X 2 matrices having all terms in {-n,...,0,..,n} and permanent=trace.at n=28A211145
- a(n) = 3*B*C*(n mod A) + 5*A*C*(n mod B) + 2*A*B*(n mod C) with A=7, B=11, C=17.at n=5A256668
- Sum over all partitions lambda of n into 5 distinct parts of Product_{i:lambda} prime(i).at n=2A258360
- Coefficient of y^0 in G(x,y)^4 where G(x,y) = Sum_{n=-oo..+oo} (1-x^n)^n * x^n * y^n.at n=22A263189
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 217", based on the 5-celled von Neumann neighborhood.at n=22A270911
- Number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 453", based on the 5-celled von Neumann neighborhood.at n=47A272273
- a(n) = sum of the perimeters of the Ferrers boards of the partitions of n. Also, sum of the perimeters of the diagrams of the regions of the set of partitions of n.at n=17A278355