15028
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 30086
- Proper Divisor Sum (Aliquot Sum)
- 15058
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 6528
- Möbius Function
- 0
- Radical
- 442
- Omega Function (Ω)
- 5
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 89
- 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) = Sum{T(i,j)}, 0<=i<=n, 0<=j<=n, T given by A026703.at n=11A026712
- Expansion of (3+2*x^2)/(1-x)^4.at n=25A037236
- Expansion of Product_{m>=1} 1/(1-x^m)^A000009(m).at n=20A089259
- Triangle read by rows: T(n,k) is the number of peakless Motzkin paths of length n and having k ladders.at n=52A098093
- Expansion of (1 + x - x^3 - 2*x^4)/(1 - x^2 - x^3 - x^4 - x^5).at n=25A109544
- 13 times the squares: a(n) = 13*n^2.at n=34A152742
- Number of binary strings of length n with equal numbers of 00010 and 11001 substrings.at n=15A164225
- Numbers n such that the sum of prime factors of n (counted with repetition) equals three times the largest prime divisor.at n=43A212861
- Expansion of x*(1+11*x-10*x^3)/(1-12*x^2+10*x^4).at n=7A249312
- Chebyshev S polynomial (A049310) evaluated at x = 26/7 and multiplied by powers of 7 (A000420).at n=3A249863
- Number of (n+1)X(7+1) arrays of permutations of 0..n*8+7 with each element having directed index change -2,-2 -1,0 0,1 or 1,0.at n=3A264533
- T(n,k)=Number of (n+1)X(k+1) arrays of permutations of 0..(n+1)*(k+1)-1 with each element having directed index change -2,-2 -1,0 0,1 or 1,0.at n=48A264534
- Number of (4+1) X (n+1) arrays of permutations of 0..n*5+4 with each element having directed index change -2,-2 -1,0 0,1 or 1,0.at n=6A264537
- Number of n X 3 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.at n=6A281051
- T(n,k)=Number of nXk 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.at n=42A281056
- Number of 7Xn 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.at n=2A281062
- G.f.: Product_{n=-oo..+oo} (1 + x^n*(1 + x^n)^n).at n=25A293603
- a(n) = 3*n^3 + n^2.at n=17A294315
- Primitive abundant numbers version 2 (abundant numbers all of whose proper divisors are deficient numbers) and increasing any prime factor in the prime factorization gives a non-abundant number when factored back.at n=25A335557
- Numbers that are the sum of eight fourth powers in seven or more ways.at n=31A345582