15892
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 28980
- Proper Divisor Sum (Aliquot Sum)
- 13088
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7616
- Möbius Function
- 0
- Radical
- 7946
- Omega Function (Ω)
- 4
- 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
- 97
- 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
- Consider the trajectory of n under the iteration of a map which sends x to 3x - sigma(x) if this is >= 0; otherwise the iteration stops. The sequence gives values of n which eventually reach 0.at n=36A037159
- Denominators of continued fraction convergents to sqrt(974).at n=10A042885
- Numbers k such that 3*10^k + 1*R_k is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=17A056704
- Numbers n such that sigma(n) + sigma(n+3) = sigma(n+1) + sigma(n+2).at n=2A076666
- Numbers k such that numerator(Bernoulli(2*k)/(2*k)) is different from numerator(Bernoulli(2*k)/(2*k*(2*k-1))).at n=61A090495
- Noncrossing forests in the regular (n+1)-polygon obtained by a grafting procedure.at n=6A200757
- Majority value maps: number of n X 3 binary arrays indicating the locations of corresponding elements equal to at least half of their king-move neighbors in a random 0..2 n X 3 array.at n=4A220192
- T(n,k)=Majority value maps: number of nXk binary arrays indicating the locations of corresponding elements equal to at least half of their king-move neighbors in a random 0..2 nXk array.at n=23A220194
- T(n,k)=Majority value maps: number of nXk binary arrays indicating the locations of corresponding elements equal to at least half of their king-move neighbors in a random 0..2 nXk array.at n=25A220194
- Majority value maps: number of nX3 binary arrays indicating the locations of corresponding elements equal to at least half of their king-move neighbors in a random 0..3 nX3 array.at n=4A220356
- T(n,k)=Majority value maps: number of nXk binary arrays indicating the locations of corresponding elements equal to at least half of their king-move neighbors in a random 0..3 nXk array.at n=23A220358
- T(n,k)=Majority value maps: number of nXk binary arrays indicating the locations of corresponding elements equal to at least half of their king-move neighbors in a random 0..3 nXk array.at n=25A220358
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 678", based on the 5-celled von Neumann neighborhood.at n=43A273409
- Solution (a(n)) of the complementary equation a(n) = 2*a(n-1) - a(n-2) + b(n); see Comments.at n=41A305129
- a(n) is the smallest number which can be represented as the sum of four distinct nonzero n-gonal numbers in exactly n ways, or -1 if no such number exists.at n=14A374274