6889
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 31
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 3
- Divisor Sum
- 6973
- Proper Divisor Sum (Aliquot Sum)
- 84
- 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
- 6806
- Möbius Function
- 0
- Radical
- 83
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 1
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- yes
- 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
- 181
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- no
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- yes
- Achilles Number
- no
- Perfect Power
- yes
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Strobogrammatic numbers: the same upside down.at n=27A000787
- Squares of primes.at n=22A001248
- Sum of squares of primes = 2 mod 3 dividing n.at n=82A005075
- Sum of squares of primes = 3 mod 4 dividing n.at n=82A005083
- Coordination sequence for sigma-CrFe, Position Xc.at n=21A009961
- Numbers m such that phi(m) * sigma(m) + k^2 is not a square for any k.at n=28A015713
- Odd squares: a(n) = (2n+1)^2. Also centered octagonal numbers.at n=41A016754
- a(n) = (3n+2)^2.at n=28A016790
- a(n) = (4n + 3)^2.at n=20A016838
- a(n) = (5*n + 3)^2.at n=16A016886
- a(n) = (6*n + 5)^2.at n=13A016970
- a(n) = (7*n + 6)^2.at n=11A017054
- a(n) = (8n + 3)^2.at n=10A017102
- a(n) = (9*n + 2)^2.at n=9A017186
- a(n) = (10*n + 3)^2.at n=8A017306
- a(n) = (11*n + 6)^2.at n=7A017462
- a(n) = (12*n + 11)^2.at n=6A017654
- Powers of fourth root of 8 rounded to nearest integer.at n=17A018067
- Powers of fourth root of 8 rounded up.at n=17A018068
- Strobogrammatic squares: the same upside down (probably finite).at n=2A018848