6601
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 8064
- Proper Divisor Sum (Aliquot Sum)
- 1463
- 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
- 5280
- Möbius Function
- -1
- Radical
- 6601
- 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
- 75
- 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
- yes
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Deceptive nonprimes: composite numbers k that divide the repunit R_{k-1}.at n=14A000864
- 10-gonal (or decagonal) numbers: a(n) = n*(4*n-3).at n=41A001107
- Fermat pseudoprimes to base 2, also called Sarrus numbers or Poulet numbers.at n=17A001567
- Carmichael numbers: composite numbers k such that a^(k-1) == 1 (mod k) for every a coprime to k.at n=5A002997
- Number of nonequivalent dissections of an n-gon into 3 polygons by nonintersecting diagonals up to rotation.at n=40A003451
- Tetrahedral numbers written backwards.at n=39A004161
- Spiral sieve using Fibonacci numbers.at n=18A005621
- Pseudoprimes to base 3.at n=19A005935
- Pseudoprimes to base 5.at n=14A005936
- Pseudoprimes to base 6.at n=21A005937
- Pseudoprimes to base 10.at n=24A005939
- Euler pseudoprimes: composite numbers n such that 2^((n-1)/2) == +-1 (mod n).at n=11A006970
- Composite numbers k such that k == +-1 (mod 8) and 2^((k-1)/2) == 1 (mod k).at n=8A006971
- Generalized Fibonacci numbers: a(n) = a(n-1) + 11*a(n-2).at n=7A015447
- Fermat pseudoprimes to base 4.at n=35A020136
- Pseudoprimes to base 9.at n=41A020138
- Pseudoprimes to base 11.at n=22A020139
- Pseudoprimes to base 12.at n=30A020140
- Pseudoprimes to base 13.at n=22A020141
- Pseudoprimes to base 15.at n=15A020143