9955
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 13104
- Proper Divisor Sum (Aliquot Sum)
- 3149
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7200
- Möbius Function
- -1
- Radical
- 9955
- Omega Function (Ω)
- 3
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 91
- 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
- Sum along upward diagonal of Pascal triangle from (but not including) halfway point.at n=21A010758
- a(n) = s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n-k+1), where k = floor( n/2 ), s = natural numbers >= 3.at n=43A024875
- T(n, 2n-9), T given by A027926.at n=10A027932
- a(n) = T(2n+1, n+3), T given by A027948.at n=5A027955
- a(n) = greatest number in row n of array T given by A027948.at n=15A027957
- Number of words of length 4 in the n(n-1)/2 transpositions of S[ n ] equivalent to the identity.at n=10A029699
- Numbers of the form p*q*r where p,q,r are distinct odd palindromic primes (odd terms from A002385).at n=36A046405
- Partial sums of A053739.at n=9A053295
- T(n,n-3), array T as in A054106.at n=38A054107
- Numbers n such that the trinomial x^n + x + 1 is irreducible over GF(5).at n=22A058334
- Numbers k such that 2^k - 15 is prime.at n=24A059612
- Diagonal in array of n-gonal numbers A081422.at n=21A081435
- Pascal-(1,5,1) array.at n=62A081580
- Pascal-(1,5,1) array.at n=58A081580
- Fourth row of Pascal-(1,5,1) array A081580.at n=7A081590
- 45-gonal numbers: n*(43*n-41)/2.at n=21A098924
- Berend Jan van der Zwaag's conjectured complete list of numbers that start different "expanding periodic loops" under the mapping described in A053392 and A060630.at n=9A103117
- Number of permutations of length n which avoid the patterns 3412, 4123, 4321.at n=8A116737
- Numbers such that the sum of the factorials of the digits of the cube is a square.at n=30A126076
- Number of partitions of n such that the largest part is coprime to every other part.at n=39A130690