15375
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 26208
- Proper Divisor Sum (Aliquot Sum)
- 10833
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8000
- Möbius Function
- 0
- Radical
- 615
- 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
- 58
- 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
- a(n) = dot_product(n,n-1,...2,1)*(5,6,...,n,1,2,3,4).at n=36A026060
- Numbers whose base-4 representation contains exactly three 0's and four 3's.at n=10A045080
- Expansion of (1-x)*(1-2*x)/(1-5*x+5*x^2).at n=8A052936
- Numbers k such that tau(k) - tau(k+1) = 1.at n=23A068208
- Numbers n such that RevBinary(RevDecimal(n))=RevDecimal(RevBinary(n)), where RevDecimal(n) is the decimal reversal of n (A004086) and RevBinary(n) is the binary reversal of n (A030101).at n=48A081433
- Numbers n that are the hypotenuse of exactly 10 distinct integer-sided right triangles, i.e., n^2 can be written as a sum of two squares in 10 ways.at n=34A097225
- Base 10 numbers that are palindromic in bases 2 and 4.at n=41A097856
- Integers i such that 9*i = 25 X i, but 17*i is not 49 X i.at n=16A115811
- Each term k provides a value of (sum-of-digits of 5^k)/k that is closer to Pi than the previous value.at n=14A119666
- a(n) = 16n^2 + 32n + 15.at n=30A141759
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 1, 0), (0, 1, -1), (1, 0, 1), (1, 1, 1)}.at n=7A150971
- Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n having k peaks of maximum height (1 <= k <= n).at n=56A152879
- a(n) = 961*n - 1.at n=15A158412
- Record numbers of A171063 nonzero period n solutions of x(i)=(x(i-1)+x(i-2)) mod m, as encountered in (n=1,m=1; n=1,m=2; n=2,m=1) antidiagonal order.at n=18A171061
- Record numbers of A171063 nonzero period n solutions of x(i)=(x(i-1)+x(i-2)) mod m, as encountered in (n=1,m=1; n=2,m=1; n=1,m=2) antidiagonal order.at n=19A171062
- Product of odd prime anti-factors < n, with multiplicity.at n=61A171487
- Product of two consecutive odd numbers k, k+2 such that (k*(k+2))+-2 are primes.at n=7A174383
- a(n) = (8*n+3)*(8*n+5).at n=15A177065
- The Wiener index of the windmill graph D(6,n). The windmill graph D(m,n) is the graph obtained by taking n copies of the complete graph K_m with a vertex in common (i.e., a bouquet of n pieces of K_m graphs).at n=24A180577
- a(n) = A220371(n)/(4*A220371(n-1)).at n=30A193365