2825
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 3534
- Proper Divisor Sum (Aliquot Sum)
- 709
- 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
- 2240
- Möbius Function
- 0
- Radical
- 565
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 84
- 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
- no
- Odd
- yes
Appears in sequences
- Numbers that are the sum of 2 squares in exactly 3 ways.at n=27A000443
- Expansion of x*(1+x-x^2)/((1-x)^4*(1+x)).at n=30A005744
- Sum of Gaussian binomial coefficients [n,k] for q=2 and k=0..n.at n=6A006116
- Coordination sequence T1 for Zeolite Code LTA and RHO.at n=42A008137
- Coordination sequence T1 for Zeolite Code NON.at n=32A008212
- Coordination sequence T1 for Zeolite Code SGT.at n=33A008229
- Coordination sequence T1 for Zeolite Code -ROG.at n=40A009859
- Maximal number of subgroups in a group with n elements.at n=63A018216
- Pseudoprimes to base 18.at n=24A020146
- Numbers k such that the continued fraction for sqrt(k) has period 21.at n=22A020360
- Fibonacci sequence beginning 1, 19.at n=12A022109
- a(n) = n*(9*n + 1)/2.at n=25A022267
- a(n) = 2*(n+1) + 3*n + ... + (k+1)*(n+2-k), where k = floor((n+1)/2).at n=28A024305
- Numbers that are the sum of 2 nonzero squares in exactly 3 ways.at n=25A025286
- Numbers that are the sum of 2 nonzero squares in 3 or more ways.at n=33A025294
- Numbers that are the sum of 2 distinct nonzero squares in exactly 3 ways.at n=24A025304
- Numbers that are the sum of 2 distinct nonzero squares in 3 or more ways.at n=32A025313
- a(n) = (1/1 + 1/(n-1) + ... + 1/C(n-[ n/2 ],[ n/2 ]))*L, where L = LCM{1, n-1, ..., C(n-[ n/2 ],[ n/2 ])}.at n=10A025563
- Nonsquarefree k such that Pell equation x^2 - k*y^2 = -1 is soluble.at n=24A031397
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted then there are a pair of central terms both equal to 9.at n=5A031422