9975
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 30
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 19840
- Proper Divisor Sum (Aliquot Sum)
- 9865
- 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
- 4320
- Möbius Function
- 0
- Radical
- 1995
- Omega Function (Ω)
- 5
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 166
- Smith Number
- yes
- 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
- Expansion of 1/(1-x^2-x^3-x^4-x^5-x^6-x^7-x^8-x^9).at n=22A013986
- Numbers whose base-5 representation contains exactly three 0's and two 4's.at n=29A045216
- 4-digit terms in the continued fraction for Pi.at n=20A048958
- Let u be any string of n digits from {0,...,4}; let f(u) = number of distinct primes, not beginning with 0, formed by permuting the digits of u to a base-5 number; then a(n) = max_u f(u).at n=9A065846
- Largest eigenvalue, rounded to the nearest integer, of a rank n matrix of 1..n^2 filled successively along rows.at n=26A072333
- Number of planar partitions of n with exactly 3 rows.at n=16A091357
- Fifth column (m=4) of (1,3)-Pascal triangle A095660.at n=18A095661
- Triangle T(n,k) read by rows: (1/n) * C(2n+k,k-1) * C(n,k); n, k >= 1.at n=31A102537
- Composite numbers between largest n-digit prime and the smallest (n+1) digit prime.at n=18A109936
- Third column of second-order Eulerian triangle A008517 divided by 2.at n=5A112498
- Triangle of numbers related to the generalized Catalan sequence C(2;n+1)=A064062(n+1), n>=0.at n=26A113647
- Second diagonal of triangle A113647 (called Y(2,1)).at n=6A115137
- Subtriangle of generalized Catalan triangle CM(1,2) = A116880.at n=20A116872
- Generalized Catalan triangle, called CM(1,2).at n=26A116880
- Number of indecomposable partitions of n.at n=32A122697
- Numbers n for which nontrivial positive magic squares of exactly 10 different orders with magic sum n exist. For a definition of nontrivial positive magic squares, see A125005.at n=18A125017
- Number of primitive multiplex juggling sequences of length n, base state <2,1> and hand capacity 2.at n=6A136778
- a(n) = n*(8*n+5).at n=35A139277
- a(n) = floor(2*(3/2)^n).at n=21A147788
- 3 times 13-gonal (or tridecagonal) numbers: a(n) = 3*n*(11*n - 9)/2.at n=25A153875