16501
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 17100
- Proper Divisor Sum (Aliquot Sum)
- 599
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 15904
- Möbius Function
- 1
- Radical
- 16501
- 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
- 40
- 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
- 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 10.at n=22A031423
- Numbers whose set of base-11 digits is {1,4}.at n=36A032823
- Numbers whose base-4 representation contains exactly three 0's and four 1's.at n=25A045032
- a(n+1) = a(n) + n (if n is odd), a(n+1) = a(n) * n (if n is even).at n=11A047904
- Numerators of continued fraction convergents to sinh(1).at n=9A078980
- Total sum of maximum list sizes in all sets of lists of n-set, cf. A000262.at n=6A097146
- Row sums of triangle A130461.at n=13A130476
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, 0, 1), (-1, 1, 1), (0, 1, 1), (1, -1, 1), (1, 1, -1)}.at n=8A149073
- Positive numbers y such that y^2 is of the form x^2 + (x + 569)^2 with integer x.at n=7A160090
- Numbers n such that n!8-2 is prime.at n=51A204664
- Numbers k such that k^3 - b2 is a triangular number (A000217), where b2 is the largest square less than k^3.at n=31A233401
- a(n) = (x(n)^2 + 1)/m(n), with m(n) = A002559(n) (Markoff numbers) and x(n)= A324601(n), for n >= 3. The Markoff uniqueness conjecture is assumed to be true.at n=28A309161
- Numbers that can be written in more than one way as p^2 + q^3 + r^4 with p, q and r primes.at n=26A318530