15111
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 9
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 23088
- Proper Divisor Sum (Aliquot Sum)
- 7977
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9504
- Möbius Function
- 0
- Radical
- 5037
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 208
- 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
- no
- Odd
- yes
Appears in sequences
- Partitions into non-integral powers (see Comments for precise definition).at n=15A000234
- Table, read by antidiagonals, of iterated binomial transforms of A095148, which also forms the antidiagonal sums shift right.at n=52A095788
- a(n) = 729*n - 198.at n=20A156772
- Numbers k such that the two closest numbers above and below k, which are in A010784 and which have no common digit with k, have the same distance to k.at n=16A160343
- Partial sums of A139250.at n=43A160424
- Triangle read by rows: number of permutation trees of power n and width <= k.at n=38A179457
- Numbers with digital product = 5.at n=13A199985
- Composite numbers whose product of digits is 5.at n=9A201054
- Construct sequences P,Q,R by the rules: Q = first differences of P, R = second differences of P, P starts with 1,3,9, Q starts with 2,6, R starts with 4; at each stage the smallest number not yet present in P,Q,R is appended to R. Sequence gives P.at n=39A225385
- Triangle T(n, k) = abs(A225483(n/2, k)) if (n mod 2 = 0), otherwise abs(A225482((n-1)/2, k) - A225483((n-1)/2, k-1)), read by rows.at n=30A225532
- Triangle T(n, k) = abs(A225483(n/2, k)) if (n mod 2 = 0), otherwise abs(A225482((n-1)/2, k) - A225483((n-1)/2, k-1)), read by rows.at n=33A225532
- Smallest number x such that phi(x) = phi(x(n)), where x(n) is the n-th arithmetic derivatives of x and x is not equal to x(n).at n=15A246775
- Number of (n+1) X (2+1) 0..2 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.at n=4A250892
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.at n=19A250898
- Number of (5+1) X (n+1) 0..2 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.at n=1A250903
- Numbers using only digits 1 and 5.at n=38A276037
- Number of points that are the intersections of exactly two semicircles in the configuration A290447(n).at n=27A292103
- Numbers k such that the average of squarefree kernels of all positive integers <= k is an integer.at n=11A303480
- Numbers whose digit product equals the number of their digits.at n=19A321771
- Number of permutations of length n with at most two descents.at n=9A326355