6806
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 10584
- Proper Divisor Sum (Aliquot Sum)
- 3778
- 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
- 3280
- Möbius Function
- -1
- Radical
- 6806
- 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
- yes
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 62
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = (3*n+1)*(3*n+2).at n=27A001504
- a(n) = 2*n*(2*n+1).at n=41A002943
- Coordination sequence for sigma-CrFe, Position Xf.at n=21A009958
- Coordination sequence for sigma-CrFe, Position Xd.at n=21A009959
- a(0) = 1, a(n) = 21*n^2 + 2 for n>0.at n=18A010011
- Self-convolution of composite numbers.at n=21A023648
- Sorted Galois numbers.at n=26A028689
- Product of a prime and the previous number.at n=22A036689
- Numbers n such that there are equal numbers of 0's and 1's in first n digits of binary representation of Pi.at n=39A039624
- Numbers whose base-4 representation contains exactly three 1's and four 2's.at n=12A045104
- Totients of consecutive pure powers of primes.at n=47A053198
- McKay-Thompson series of class 45b for Monster.at n=49A058686
- Numbers of the form 12*k + 2 with nonempty inverse totient set.at n=6A063668
- Engel expansion of sinh(1).at n=41A068377
- Deficient oblong numbers.at n=12A077804
- Numbers divisible by prime ceilings of their square roots + 1.at n=44A079143
- Sum of smallest parts of all partitions of n into distinct parts.at n=47A092265
- Squarefree oblong (pronic) numbers having an odd number of prime factors.at n=14A098827
- Numbers n such that every digit of n and n-th prime contains a loop (only digits 0,4,6,8,9 in n and n-th prime).at n=10A107624
- Numbers n such that phi(n) = phi(n + phi(n)).at n=37A108569