15281
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 18240
- Proper Divisor Sum (Aliquot Sum)
- 2959
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12528
- Möbius Function
- -1
- Radical
- 15281
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- 32
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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) = s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n-k+1), where k = [ n/2 ], s = (1, p(1), p(2), ...).at n=27A025099
- Sum of squares of digits of n is equal to the largest prime factor of n reversed, where the largest prime factor is not a palindrome.at n=25A074303
- Cardinality of set of sets of parts of all partitions of n.at n=46A088314
- E.g.f. satisfies: A(x/A(x)^4) = exp(x).at n=4A144684
- Number of (n+1) X (2+1) 0..2 arrays with no 2 X 2 subblock having the maximum of its diagonal elements greater than the absolute difference of its antidiagonal elements.at n=3A251107
- Number of (n+1)X(4+1) 0..2 arrays with no 2X2 subblock having the maximum of its diagonal elements greater than the absolute difference of its antidiagonal elements.at n=1A251109
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with no 2X2 subblock having the maximum of its diagonal elements greater than the absolute difference of its antidiagonal elements.at n=11A251113
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with no 2X2 subblock having the maximum of its diagonal elements greater than the absolute difference of its antidiagonal elements.at n=13A251113
- 9-step Fibonacci sequence starting with 0,0,0,1,0,0,0,0,0.at n=23A251750
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 966", based on the 5-celled von Neumann neighborhood.at n=36A273837
- Compound filter: a(n) = P(sigma(n), sigma(2n)), where P(n,k) is sequence A000027 used as a pairing function, and sigma is the sum of divisors (A000203).at n=27A286359
- Decimal representation of the diagonal from the corner to the origin of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 350", based on the 5-celled von Neumann neighborhood.at n=26A287755
- Odd composite integers m such that U(m)^2 == 1 (mod m) and V(m) == 6 (mod m), where U(m) and V(m) are the m-th generalized Lucas and Pell-Lucas numbers of parameters a=6 and b=-1, respectively.at n=18A337629
- Odd composite integers m such that A085447(m) == 6 (mod m).at n=25A338078
- Setwise difference A340150 \ A340076.at n=35A340151
- Number of ways to write n as an ordered sum of 5 prime powers (including 1).at n=35A341134