15785
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 24192
- Proper Divisor Sum (Aliquot Sum)
- 8407
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9600
- Möbius Function
- 1
- Radical
- 15785
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
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
- 177
- 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) is the solution to the postage stamp problem with 5 denominations and n stamps.at n=20A001210
- Alkane (or paraffin) numbers l(7,n).at n=27A005994
- Expansion of e.g.f. sin(log(x+1) - arcsin(x)).at n=9A013222
- Expansion of e.g.f. arcsinh(log(x+1) - arcsin(x)).at n=9A013228
- Numbers whose base-5 representation contains exactly three 0's and three 1's.at n=28A045172
- a(n) = n*(n-1)*(2*n^2 + 1)/6.at n=15A071245
- Expansion of (1-x)/(1-x+x^2-2*x^3).at n=39A078015
- Fourth column of (1,5)-Pascal triangle A096940.at n=40A096941
- Denominators of a-sequence for Sheffer matrix A130191 (Stirling2 squared).at n=40A130409
- Number of partitions of n such that neither the number of parts nor the number of distinct parts is a part.at n=39A241380
- The number of central quasigroups (also known as T-quasigroups, or quasigroups affine over an abelian group) of order n, up to isomorphism.at n=55A260645
- Number of ways to trisect a hexagon with side length n exactly into three identical parts in a triangular lattice.at n=3A268606
- Number of distinct length-n blocks (a.k.a. subword complexity) of Möbius function mu(n) (A008683).at n=10A280466
- Number of n-element subsets of [n+4] having an even sum.at n=27A282080
- Indices of primes followed by a gap (distance to next larger prime) of 42.at n=43A320719
- Products k of 4 distinct primes (or tetraprimes) such that k has no squarefree neighbors.at n=17A364141
- Sum of those numbers t which have a unique representation as the sum of floor(n/2) distinct squares from among 1^2,...,n^2.at n=9A374510