17408
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 22
- Divisor Sum
- 36846
- Proper Divisor Sum (Aliquot Sum)
- 19438
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8192
- Möbius Function
- 0
- Radical
- 34
- Omega Function (Ω)
- 11
- 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
- 22
- 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
- Expansion of cos x (1 + sin x ) /cos 2x.at n=7A000825
- E.g.f. cos(x)/(cos(x) - sin(x)).at n=7A000828
- Coefficients of completely replicable function "6d".at n=17A007263
- Expansion of tan(tan(x)^2)/2.at n=4A024290
- Numbers k that divide the (right) concatenation of all numbers <= k written in base 2 (most significant digit on left).at n=43A029447
- Sums of 2 distinct powers of 4.at n=26A038470
- phi(n) is equal to the product of the dual prime-power components of n-1 (i.e., A008477(n-1)).at n=6A039783
- First differences of A045623.at n=13A045891
- Octahedral torus number: a(n) = n^2 + 2*(Sum_{k=1..n-1} k^2) - 2*(floor((n+1)/2)^2 + 2*(Sum_{k=1..floor((n+1)/2)-1} k^2)) + (1 - (-1)^n)/2.at n=32A050442
- Denominators of coefficients of 1/2^(2n+1) in Newton's series for Pi.at n=8A054388
- Sums of two powers of 4.at n=33A055236
- Number of permutations of n elements with an odd number of fixed points.at n=8A063083
- Numbers which can be written as b^2*c^2*(b^2+c^2).at n=24A063663
- Volume (multiplied by 3) of polyhedron formed by points (i,j,k) in Z^3 with i^2+j^2+k^2 = n^2.at n=12A065089
- Sum of all partitions of n into distinct parts.at n=34A066189
- a(n) = (3*n-2)*2^(n-3).at n=10A066373
- 11-almost primes (generalization of semiprimes).at n=17A069272
- Solutions to phi(gpf(x)) - gpf(phi(x)) = 14 = c are special multiples of 17, x = 17k, where greatest prime factors of factor k were observed from {2, 3, 5}, i.e., it is smaller than 17. See solutions to other even cases of c (=A070813): A007283 for 0, A070004 for 2, A070815 for 254, A070816 for 65534. Gpf = greatest prime factor.at n=34A070814
- Numbers k such that the number of steps to reach 1 in '3x+1' problem equals tau(k), the number of divisors of k.at n=24A070980
- Numbers n such that phi(n) = b(n,1)^b(n,0) where b(n,1) is the number of 1's in binary representation of n and b(n,0) the number of 0's.at n=45A071638