15005
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 18012
- Proper Divisor Sum (Aliquot Sum)
- 3007
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12000
- Möbius Function
- 1
- Radical
- 15005
- 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
- 63
- 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) = floor(Fibonacci(n)/5).at n=25A004698
- a(n) = ceiling(n*phi^15), where phi is the golden ratio, A001622.at n=11A004970
- Rectangular array of numbers Fibonacci(m(n+1))/Fibonacci(m), m >= 1, n >= 0, read by downward antidiagonals.at n=40A028412
- Integers that appear as ratios of Fibonacci numbers F(kn)/F(k), but omitting Fibonacci numbers F(n)/F(1) and Lucas numbers F(2n)/F(n).at n=15A031122
- Denominators of continued fraction convergents to sqrt(125).at n=8A041227
- Denominators of continued fraction convergents to sqrt(500).at n=12A041955
- Numbers having four 2's in base 9.at n=24A043464
- a(n) = Fibonacci(5*n)/5.at n=5A049666
- a(n) = F(n^2)/F(n), where F(n) = A000045(n) is the n-th Fibonacci number.at n=4A051294
- a(n) = F(n) / Product_{p|n} F(p), where F(k) is k-th Fibonacci number and the p's in product are the distinct primes dividing n.at n=24A051348
- a(n) = n^4 + 3*n^2 + 1.at n=11A057721
- Primitive part of Fibonacci(n).at n=24A061446
- Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=2, r=3, I={-1,0}.at n=23A080008
- Numbers n such that mu(n) + mu(n+1) + mu(n+2) + mu(n+3) + mu(n+4) + mu(n+5) + mu(n+6) = 6.at n=14A082967
- Numbers generated by the Fibonacci polynomial x^4 + 3x^2 + 1.at n=10A085151
- First differences of Chebyshev polynomials S(n,123) = A049670(n+1) with Diophantine property.at n=2A097843
- a(n) = Fibonacci(5n)/Fibonacci(n).at n=4A103326
- Numbers k such that k and k^2 use only the digits 0, 1, 2 and 5.at n=49A136822
- Numbers k such that k and k^2 use only the digits 0, 1, 2, 5 and 7.at n=59A136824
- Numbers k such that k and k^2 use only the digits 0, 1, 2, 5 and 8.at n=59A136825