10581
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 14112
- Proper Divisor Sum (Aliquot Sum)
- 3531
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7052
- Möbius Function
- 1
- Radical
- 10581
- Omega Function (Ω)
- 2
- 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
- 117
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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 e.g.f. exp(log(1+x)/cos(x)).at n=9A009196
- 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 68.at n=33A031566
- Numbers whose base-2 representation has exactly 13 runs.at n=2A043580
- a(n) = T(n,n-3), array T as in A055818.at n=36A055820
- a(n) = ((6*n+1)*4^n - 1)/3.at n=5A072258
- a(n) = (n-1)*(n-2)^3 - A003878(n-3), with a(1) = a(2) = 0 and a(3) = 2.at n=25A075681
- Integers k such that 10^k + 33 is prime.at n=20A107084
- Least numbers, starting (1,1,1), such that determinants of continuous blocks of 4 form an increasing sequence of primes (A119839).at n=10A119838
- Sequence M_n arising in enumeration of arrays of directed blocks (see 2007 Quaintance reference for precise definition). [The next term is not an integer.].at n=6A129872
- a(n) = 529*n + 1.at n=19A158368
- a(n) = 20*n^2 + 1.at n=23A158493
- a(n) = n*2^(n+1) + (2^(n+3)+(-1)^n)/3.at n=9A191007
- a(n) = 5*n^2 + 1.at n=46A212656
- Semiprimes of the form 5*n^2 + 1.at n=13A212707
- Number of idempotent 3 X 3 0..n matrices of rank 2.at n=40A224334
- Decimal representation of the middle column of the "Rule 41" elementary cellular automaton starting with a single ON (black) cell.at n=13A266613
- Numbers written in binary balanced system (A270885) that have exactly one zero.at n=43A270886
- Number of grid points covered by a truncated triangle drawn on the hexagonal lattice with the short sides having length n and the long sides length 2*n.at n=40A342914
- a(n) = 8*n^3 - 6*n - 1.at n=11A369922
- a(n) = Sum_{j=1..n} Sum_{k=1..n} phi(j*k).at n=16A372633