9505
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 11412
- Proper Divisor Sum (Aliquot Sum)
- 1907
- 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
- 7600
- Möbius Function
- 1
- Radical
- 9505
- 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
- 122
- 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
- Weighted count of partitions with odd parts.at n=42A005896
- Expansion of exp(sin(x))/cos(x).at n=9A009207
- Expansion of e.g.f. sinh(sin(x))/cos(x) (odd powers only).at n=4A009592
- Number of partitions satisfying (cn(0,5) <= cn(1,5) = cn(4,5)).at n=48A036809
- Number of partitions satisfying (cn(2,5) = cn(3,5) and cn(0,5) <= cn(1,5) and cn(0,5) <= cn(4,5) and cn(2,5) <= cn(1,5) and cn(2,5) <= cn(4,5)).at n=49A036811
- Number of partitions satisfying (cn(0,5) = 0 and cn(1,5) = cn(4,5)).at n=52A036818
- Denominators of continued fraction convergents to sqrt(150).at n=4A041275
- Denominators of continued fraction convergents to sqrt(600).at n=4A042151
- Numbers n such that n^2 can be obtained from n by inserting internal (but not necessarily contiguous) digits.at n=40A046851
- Numbers k such that prime(k) + prime(k+1)*2 is a square.at n=21A064504
- Centered 18-gonal numbers.at n=32A069131
- Group successively larger prime numbers so that the sum of the n-th group is a multiple of n. Sequence gives the group sum divided by n for the n-th group.at n=39A074131
- Starting with a(0) = 1, smallest squarefree number k such that, for all a(m), m < n, k + a(m) is not squarefree.at n=12A077225
- Expansion of (1-x)^(-1)/(1+x+x^2-x^3).at n=32A077908
- Starting with a(0) = 1, smallest number k > a(n-1) such that, for all a(m) with m < n, k + a(m) is not squarefree.at n=11A080793
- Natural numbers written out with their digits grouped in sets of four (leading zeros omitted).at n=22A091332
- a = a(n) is such that the a-th prime p(a) is the least prime with digital sum equal to n, or a(n)=0 if no such prime exists.at n=43A104290
- Number of triple descents (i.e., ddd's) in all paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(2,1),U=(1,2), or d=(1,-1).at n=3A108444
- Numbers of the form k^2 - k - 1 whose digit sum is also a number of the form k^2 - k - 1.at n=35A117746
- Start with 1057 and repeatedly reverse the digits and add 2 to get the next term.at n=3A120215