8617
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9856
- Proper Divisor Sum (Aliquot Sum)
- 1239
- 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
- 7380
- Möbius Function
- 1
- Radical
- 8617
- 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
- 171
- 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
- Numbers k such that Fib(k) == 13 (mod k).at n=39A023178
- Convolution of A023531 and Fibonacci numbers.at n=20A023557
- Convolution of A023531 and (F(2), F(3), F(4), ...).at n=19A023561
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 50 ones.at n=29A031818
- a(n) is the number of subsequences {s(k)} of {1,2,3,...n} such that s(k+1)-s(k) is 1 or 3.at n=19A050228
- a(n) = 2*prime(n)^2 - prime(n+1)^2.at n=24A064051
- a(n) = number of k's that make primorial P(n)/A019565(k)+A019565(k) prime, A019565(k)^2<=P(n).at n=15A103787
- Start to read the sequence digit by digit and erase the first "1" you encounter, then the first "2", the first "3", etc., until the first "0"; go on from there and erase again the first "1", the first "2", etc., until "0" -- and so on, cyclically until the end of the (infinite) sequence. Concatenate what is left. The result is the concatenation of all integers of the sequence.at n=10A108710
- Smaller of two consecutive lucky numbers with the same digital sum.at n=34A118566
- a(n+3) = (8 - 3*n)*a(n-1) + (-24 + 4*n)*a(n) + (22 - n)*a(n+1) - 8*a(n+2).at n=4A130591
- Numerator of expression W_n occurring in analysis of bubble sort.at n=7A190186
- a(n) = a(n-1) + a(n-2) + a(n-3), with a(0) = 1, a(1) = a(2) = 9.at n=13A214831
- Number of partitions p of n such that mean(p) < multiplicity(min(p)).at n=36A240203
- Number of matchings in the n X n knight graph.at n=3A287225
- Number of nX4 0..1 arrays with every element equal to 2, 3, 4, 5 or 7 king-move adjacent elements, with upper left element zero.at n=5A298625
- Number of nX6 0..1 arrays with every element equal to 2, 3, 4, 5 or 7 king-move adjacent elements, with upper left element zero.at n=3A298627
- T(n,k)=Number of nXk 0..1 arrays with every element equal to 2, 3, 4, 5 or 7 king-move adjacent elements, with upper left element zero.at n=39A298629
- T(n,k)=Number of nXk 0..1 arrays with every element equal to 2, 3, 4, 5 or 7 king-move adjacent elements, with upper left element zero.at n=41A298629
- Coordination sequence for "svh" 3D uniform tiling.at n=41A299283
- Number of nX2 0..1 arrays with every element unequal to 2, 3, 5 or 7 king-move adjacent elements, with upper left element zero.at n=13A304257