2786
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 4800
- Proper Divisor Sum (Aliquot Sum)
- 2014
- 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
- 1188
- Möbius Function
- -1
- Radical
- 2786
- 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
- 35
- 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
- Sum of Fermat coefficients.at n=10A000967
- Companion Pell numbers: a(n) = 2*a(n-1) + a(n-2), a(0) = a(1) = 2.at n=9A002203
- a(n) = floor(n*phi^11), where phi is the golden ratio, A001622.at n=14A004926
- a(n) = round(n*phi^11), where phi is the golden ratio, A001622.at n=14A004946
- Number of aperiodic binary necklaces of length n with no subsequence 00, excluding the necklace "0".at n=22A006206
- A continued cotangent.at n=2A006266
- Coordination sequence T1 for Zeolite Code STI.at n=36A008234
- Coordination sequence T2 for Zeolite Code RTE.at n=36A009891
- Expansion of 1/((1-x)(1-2x)(1-7x)(1-9x)).at n=3A021229
- Numbers k such that Hofstadter Q-sequence Q(k) (A005185) satisfies Q(k) = k/2.at n=38A027619
- a(n+1) = Sum_{k=0..floor(n/4)} a(k) * a(n-k).at n=17A030034
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 52.at n=4A031550
- Number of cyclic compositions of n into parts >= 2.at n=22A032190
- Numerators of continued fraction convergents to sqrt(8).at n=8A041010
- Numerators of continued fraction convergents to sqrt(200).at n=2A041370
- Numbers whose base-14 representation has exactly 4 runs.at n=26A043665
- Numbers n such that string 3,5 occurs in the base 9 representation of n but not of n-1.at n=38A044283
- Numbers n such that string 8,6 occurs in the base 10 representation of n but not of n-1.at n=29A044418
- Numbers n such that string 3,5 occurs in the base 9 representation of n but not of n+1.at n=38A044664
- Numbers n such that string 8,6 occurs in the base 10 representation of n but not of n+1.at n=29A044799