10561
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 10800
- Proper Divisor Sum (Aliquot Sum)
- 239
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10324
- Möbius Function
- 1
- Radical
- 10561
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 55
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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) = n^6 - (883/60)*n^5 + (157/3)*n^4 + (2155/12)*n^3 - (4570/3)*n^2 + (42767/15)*n - 967.at n=2A028295
- Number of partitions in parts not of the form 21k, 21k+3 or 21k-3. Also number of partitions with at most 2 parts of size 1 and differences between parts at distance 9 are greater than 1.at n=37A035981
- Centered 20-gonal (or icosagonal) numbers.at n=32A069133
- a(1) = 2, a(n+1) is the largest squarefree number < 2*a(n).at n=14A076994
- a(n) = 12*a(n-2) - 25*a(n-4) with initial terms 1,1,7,12.at n=9A083335
- Composite numbers such that all divisors >1 have the same number of 1's in binary representation.at n=28A089042
- Triangle read by rows: T(n,k) is the number of stacks of n pancakes requiring k = 0, ..., A058986(n) flips to sort.at n=41A092113
- Consider the triangle in which the j-th row begins with prime(j) and is the arithmetic progression with least common difference such that the remaining j-1 terms are composite and not divisible by prime(j). Sequence gives last term in each row.at n=36A095182
- Expansion of -(x+2*x^2+3*x^3-1+5*x^4)/((x+1)*(x^2-3*x+1)*(1+x^2)).at n=13A109786
- a(n) = dimension of the space in which the sphere of radius n is of maximum volume.at n=40A121546
- Binomial transform of [1, 3, 7, 0, 0, 0, ...].at n=55A140063
- Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1010-1111 pattern in any orientation.at n=12A146427
- a(n) = 5*n^2 + 20*n + 1.at n=44A162316
- Number of binary strings of length n with no substrings equal to 0000 0101 or 1010.at n=12A164434
- Arises in a refined modular approach to the Diophantine equation x^2+y^62=z^3.at n=12A172408
- Where records occur in A039996.at n=9A178597
- First appearance of n in A039996: Primes embedded in prime(n).at n=11A179908
- a(n) = 12*n^2 - 8*n + 1.at n=30A185212
- Number of (n+5) X 11 0..1 matrices with each 6 X 6 subblock idempotent.at n=6A224575
- Number of (n+5)X12 0..1 matrices with each 6X6 subblock idempotent.at n=5A224576