16526
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 24792
- Proper Divisor Sum (Aliquot Sum)
- 8266
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8262
- Möbius Function
- 1
- Radical
- 16526
- 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
- 159
- 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
- yes
- Odd
- no
Appears in sequences
- Number of partitions satisfying cn(0,5) <= cn(2,5) + cn(3,5).at n=36A039840
- Main diagonal of table A083087.at n=8A083090
- Number of 2's in n-th "Kolakoski" string defined in A054349.at n=24A111123
- Triangle read by rows generated from the Narayana transform.at n=20A117297
- Records in A118878.at n=7A119903
- Number of binary words of length n containing at least one subword 10^{6}1 and no subwords 10^{i}1 with i<6.at n=43A143286
- G.f. satisfies: A(x) = B(x*A(x)) where A(x) = Sum_{n>=0} a(n)*x^n/[n!*(n+1)!/2^n] and B(x) = Sum_{n>=0} x^n/[n!*(n+1)!/2^n].at n=5A155926
- a(n+1) = a(n) + n*a(n-1) - a(n-2) + a(n-3).at n=11A170941
- Second crank moment minus second rank moment: M_2(n) - N_2(n) = 2*spt(n).at n=24A211982
- Triangle read by rows: distribution of adjacent transpositions in involutions.at n=36A217876
- a(n) = Sum_{d|n} d^2 * (d+1)/2.at n=29A278403
- Expansion of 1/(1 + x^2 + x^3/(1 + x^5 + x^7/(1 + x^11 + x^13/(1 + ... + x^prime(2*k)/(1 + x^prime(2*k+1) + ...))))), a continued fraction.at n=52A292801
- Numbers k such that k, k+1, k+2, k+3 and k+4 are terms of A288041.at n=1A336221
- Consider the figure made up of a row of n adjacent congruent rectangles, with diagonals of all possible rectangles drawn; a(n) is the number of interior vertices where exactly four lines cross.at n=43A336490
- Number of unlabeled connected simple graphs with n edges rooted at one distinguished vertex.at n=10A339039