15080
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 32
- Divisor Sum
- 37800
- Proper Divisor Sum (Aliquot Sum)
- 22720
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5376
- Möbius Function
- 0
- Radical
- 3770
- Omega Function (Ω)
- 6
- Little Omega Function (ω)
- 4
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
- 133
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- a(n) = a(n-1) + a(n-1-(number of odd terms so far)).at n=36A007604
- 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 61.at n=30A031559
- Same rule as Aitken triangle (A011971) except a(0,0)=0, a(1,0)=1.at n=46A046936
- a(n) in base 12 is a repdigit.at n=41A048336
- Triangle of numbers relating two sequences A073155 and A073156.at n=35A073153
- Main diagonal sequence of triangle A073153.at n=7A073156
- Expansion of (1-x)/(1+x-2*x^2-x^3).at n=16A078038
- Numbers k such that the central binomial coefficient C(2k,k) is divisible by k^2.at n=29A121943
- Terms of A061047 ending in 0.at n=23A146950
- a(n) = n*(n+1)*(3*n^2+5*n+4)/12.at n=15A176060
- a(n) = 2*n*(9*n-1).at n=28A178574
- Number of permutations of 1..n with both permutation and its inverse having exactly 3 maxima.at n=7A180393
- a(n) = Carmichael(F(n)), where F(n) are the Fibonacci numbers.at n=25A181091
- Number of (w,x,y,z) with all terms in {1,...,n} and w+|x-y|<=|x-z|+|y-z|.at n=30A212691
- Number of (w,x,y) with all terms in {0,...,n} and w != x and x > range(w,x,y).at n=30A212969
- Number of arrays of 4 0..n integers with no sum of consecutive elements equal to a disjoint adjacent sum of an equal number of elements.at n=10A215191
- Denominators of coefficients in asymptotic expansion of log z + psi(z+1/z), where psi is the digamma function.at n=28A222804
- A bisection of A222804.at n=14A222806
- Number of palindromic compositions of n with parts in {1,2,4,6,8,10,...}.at n=32A276055
- a(n) = a(n-1) + 2*a(n-2) - a(n-3), where a(0) = 2, a(1) = 4, a(2) = 7.at n=15A287381