1595
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
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 2160
- Proper Divisor Sum (Aliquot Sum)
- 565
- 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
- 1120
- Möbius Function
- -1
- Radical
- 1595
- 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
- 73
- 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
- a(n) = n*(n+3)/2.at n=55A000096
- a(n) = Fibonacci(n+3) - 2.at n=14A001911
- a(n)=least number m such that m-a(n-1)<>a(j)-a(k) for all j,k less than m; a(1)=1, a(2)=3.at n=38A004979
- Related to representations as sums of Fibonacci numbers.at n=39A006133
- Number of strict (-1)st-order maximal independent sets in path graph.at n=14A007382
- Coordination sequence T1 for Zeolite Code CAS.at n=24A008063
- Coordination sequence T2 for Zeolite Code HEU.at n=26A008117
- Coordination sequence T1 for Zeolite Code MEI.at n=29A008146
- Coordination sequence T1 for Zeolite Code -ROG.at n=30A009859
- a(n) = floor( n*(n-1)*(n-2)/11 ).at n=27A011893
- First coordinate of fundamental unit of real quadratic field with discriminant A003658(n), n >= 2.at n=40A014000
- a(n) = n*(2*n-3).at n=29A014107
- a(n) = 11*a(n-1) + 12*a(n-2).at n=4A015609
- Numbers k such that phi(k + 11) | sigma(k).at n=37A015831
- Expansion of 1/(1 - x^10 - x^11 - ...).at n=56A017904
- Fibonacci sequence beginning 0, 29.at n=10A022363
- a(n) = s(1)*t(n) + s(2)*t(n-1) + ... + s(k)*t(n-k+1), where k = floor(n/2), s = natural numbers, t = odd natural numbers.at n=19A024862
- a(n) = Sum(a(2i-1)*a(n-2i+1), i = 1,2,...,[ (n+2)/4 ]).at n=19A024965
- a(n) = sum of the numbers between the two n's in A026338.at n=42A026341
- a(n) = Sum_{j=0..floor(n/2)} T(n,j), T given by A026736.at n=11A026744