16941
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 22592
- Proper Divisor Sum (Aliquot Sum)
- 5651
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11292
- Möbius Function
- 1
- Radical
- 16941
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 58
- 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
- a(n) = a(n-1) + a(n - 1 - number of even terms so far).at n=47A006336
- 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 86.at n=38A031584
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 68 ones.at n=28A031836
- Concatenate first n squares in reverse order.at n=3A038397
- Rounded volume of a regular octahedron with edge length n.at n=33A071400
- Number of n-digit "Punctual Birds" (cf. A131881).at n=5A132133
- a(n) = 484*n + 1.at n=34A158326
- The sum of the lengths of all weighted lattice paths in L_n.at n=10A182879
- a(n) = Sum_{i=0..n} digsum_5(i)^4, where digsum_5(i) = A053824(i).at n=25A231671
- a(n) = Sum_{k=1..n} prime(k+1)^prime(k).at n=2A268062
- Number of permutations of [n] avoiding {4231, 3412, 1234}.at n=12A294725
- Number of n X 2 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 0, 1 or 3 neighboring 1s.at n=8A296572
- T(n,k)=Number of nXk 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 0, 1 or 3 neighboring 1s.at n=46A296578
- Irregular table read by rows: Take a Reuleaux triangle with all diagonals drawn, as in A340639. Then T(n,k) = number of k-sided polygons in that figure for k >= 3.at n=51A340614
- Index of first occurrence of -n in A000319, or -1 if -n never appears there.at n=30A381231
- Number of medial GL-racks of order n, up to isomorphism.at n=7A383146