3605
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 4992
- Proper Divisor Sum (Aliquot Sum)
- 1387
- 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
- 2448
- Möbius Function
- -1
- Radical
- 3605
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 56
- 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
- Octagonal numbers: n*(3*n-2). Also called star numbers.at n=35A000567
- Centered tetrahedral numbers.at n=17A005894
- Coordination sequence T5 for Zeolite Code MFI.at n=38A008168
- Coordination sequence T1 for Zeolite Code ZON.at n=42A009919
- Odd octagonal numbers: (2n+1)*(6n+1).at n=17A014641
- Pseudoprimes to base 8.at n=42A020137
- Pseudoprimes to base 13.at n=17A020141
- Pseudoprimes to base 22.at n=27A020150
- Pseudoprimes to base 27.at n=30A020155
- Pseudoprimes to base 34.at n=35A020162
- Pseudoprimes to base 69.at n=21A020197
- Pseudoprimes to base 76.at n=43A020204
- Strong pseudoprimes to base 69.at n=8A020295
- Fibonacci sequence beginning 4, 13.at n=13A022132
- a(n) is least k such that k and 10k are anagrams in base n (written in base 10).at n=35A023102
- a(n) = Sum_{k=0..n} (k+1) * A026703(n, k).at n=8A027256
- Expansion of (1-x^8)*(1+x^5)/(1-x^2)^5.at n=34A027635
- Expansion of (1-x^8)*(1+x^5)/(1-x^2)^5.at n=39A027635
- a(n) = (prime(n)-1)*(prime(n)-5)/12.at n=44A030006
- Expansion of Molien series for 4-D extraspecial group 2^{1+2*2}.at n=34A030533