2806
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 4464
- Proper Divisor Sum (Aliquot Sum)
- 1658
- 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
- 1320
- Möbius Function
- -1
- Radical
- 2806
- 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
- 128
- 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
- Number of partitions into non-integral powers.at n=24A000327
- Number of 3-edge-colored connected trivalent graphs with 2n nodes.at n=5A002831
- Centered pentagonal numbers: (5n^2+5n+2)/2; crystal ball sequence for 3.3.3.4.4. planar net.at n=33A005891
- Number of irreducible positions of size n in Montreal solitaire.at n=8A007049
- Coordination sequence T4 for Zeolite Code NON.at n=32A008215
- Pisot sequence E(9,15), a(n) = floor( a(n-1)^2/a(n-2) + 1/2 ).at n=11A014003
- Numbers k such that k | 5^k + 5.at n=8A015891
- Pseudoprimes to base 9.at n=28A020138
- Pseudoprimes to base 13.at n=16A020141
- Pseudoprimes to base 25.at n=31A020153
- Pseudoprimes to base 47.at n=32A020175
- Pseudoprimes to base 73.at n=40A020201
- Pseudoprimes to base 77.at n=18A020205
- Pseudoprimes to base 95.at n=13A020223
- Numbers k such that the continued fraction for sqrt(k) has period 36.at n=34A020375
- Positive numbers k such that k and 3*k are anagrams in base 9 (written in base 9).at n=31A023080
- Number of partitions of n in which the least part is 6.at n=68A026799
- Square root of A030681.at n=16A030682
- Cube root of A030690.at n=46A030691
- Numbers whose set of base-11 digits is {1,2}.at n=24A032931