2847
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 4144
- Proper Divisor Sum (Aliquot Sum)
- 1297
- 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
- 1728
- Möbius Function
- -1
- Radical
- 2847
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 172
- 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
- no
- Odd
- yes
Appears in sequences
- Expansion of x^3*(5-2*x)*(1-x^3)/(1-x)^4.at n=24A000338
- Coefficients of modular function G_3(tau).at n=30A005761
- Coordination sequence T1 for Zeolite Code CAS.at n=32A008063
- Coordination sequence T1 for Zeolite Code LIO.at n=37A008129
- Coordination sequence T12 for Zeolite Code MFI.at n=34A008164
- Coordination sequence T4 for Zeolite Code MFI.at n=34A008167
- Coordination sequence T3 for Zeolite Code PAU.at n=39A008221
- Coordination sequence T4 for Zeolite Code -PAR.at n=38A009858
- a(n) = floor( n*(n-1)*(n-2)/26 ).at n=43A011908
- a(n) = prime(n)*(prime(n+1)-1)/2.at n=20A014303
- Number of partitions of n into distinct parts >= 3.at n=59A025148
- a(n) = A027052(n, 2n-2).at n=9A027058
- Sequence satisfies T^2(a)=a, where T is defined below.at n=45A027585
- 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 34.at n=29A031532
- In A015922, not in A033553.at n=10A033554
- a(0)=2; a(n) is the smallest k > a(n-1) such that the fractional part of k^(1/9) starts with n.at n=42A034074
- Decimal part of a(n)^(1/2) starts with reversal of its integer part: first term of runs.at n=37A034308
- Numerators of continued fraction convergents to sqrt(86).at n=8A041152
- Numbers k such that string 1,3 occurs in the base 9 representation of k but not of k-1.at n=39A044263
- Numbers n such that string 4,7 occurs in the base 10 representation of n but not of n-1.at n=31A044379