17445
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 27936
- Proper Divisor Sum (Aliquot Sum)
- 10491
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9296
- Möbius Function
- -1
- Radical
- 17445
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- 141
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- Expansion of 1/(1-x^4-x^5-x^6-x^7-x^8-x^9-x^10-x^11-x^12).at n=37A017834
- a(n) = ((2*n)!/(n!*2^(n-1)))*Integral_{x=1/2..1} (sqrt(1-x^2)/x)^(2*n) dx.at n=5A095839
- Number of permutations of length n which avoid the patterns 1234, 3421, 4312.at n=29A116756
- Duplicate of A095839.at n=5A234290
- Sum of the middle parts in the partitions of 4n-1 into 3 parts.at n=22A240707
- Numbers k such that the k-th composition in standard order is a non-alternating permutation of an initial interval of positive integers.at n=35A350250
- a(n) is the number of binary strings of length n whose shortest run of 1s is of length 3.at n=22A384155