6668
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 11676
- Proper Divisor Sum (Aliquot Sum)
- 5008
- 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
- 3332
- Möbius Function
- 0
- Radical
- 3334
- Omega Function (Ω)
- 3
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 31
- 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
- Number of trees of diameter 5.at n=20A000147
- Fibonacci sequence beginning 1, 28.at n=13A022398
- Numbers k such that 91*2^k+1 is prime.at n=6A032395
- Denominators of continued fraction convergents to sqrt(43).at n=10A041073
- Numbers having three 6's in base 10.at n=25A043515
- Numbers whose base-9 representation has exactly 5 runs.at n=15A043634
- Composite numbers not ending in zero that yield a prime when turned upside down.at n=38A048889
- Beastly (or hateful) numbers: numbers containing the string 666 in their decimal expansion.at n=14A051003
- Periodic points under the map A053392 that adds consecutive pairs of digits and concatenates them.at n=23A053393
- Numbers k such that k^2 contains only digits {2,4,6}.at n=6A053922
- Integers i > 1 for which there is no prime p such that i is a solution mod p of x^4 = 2.at n=10A065903
- Smallest of four consecutive integers divisible by four consecutive primes respectively.at n=40A072555
- Number of Fibonacci numbers F(k), k <= 10^n, which end in 8.at n=4A073555
- Left truncatable 3-almost primes, in which repeatedly deleting the leftmost digit gives a 3-almost prime at every step until a single-digit 3-almost prime remains.at n=43A085248
- Numbers k such that phi(k) + k is a fourth power.at n=14A114072
- Indices of records in A078571.at n=11A131559
- Numbers k such that k and k^2 use only the digits 0, 2, 4, 6 and 8.at n=21A136904
- Numbers k such that k and k^2 use only the digits 1, 2, 4, 6 and 8.at n=24A136994
- Numbers k such that k and k^2 use only the digits 2, 3, 4, 6 and 8.at n=14A137072
- Numbers k such that k and k^2 use only the digits 2, 4, 5, 6 and 8.at n=16A137095