9976
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 31
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 19800
- Proper Divisor Sum (Aliquot Sum)
- 9824
- 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
- 4704
- Möbius Function
- 0
- Radical
- 2494
- Omega Function (Ω)
- 5
- 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
- 135
- Smith Number
- no
- 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
- yes
- Odd
- no
Appears in sequences
- a(n+1) = n*a(n) + a(n-1) with a(0)=0, a(1)=1.at n=8A001040
- Red rooted red-black trees with n internal nodes.at n=16A001138
- Truncated cube numbers.at n=7A005912
- Even octagonal numbers: a(n) = 4*n*(3*n-1).at n=29A014642
- Powers of fourth root of 17 rounded down.at n=13A018093
- Powers of fourth root of 17 rounded to nearest integer.at n=13A018094
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly nine 1's.at n=32A020445
- a(n) = (prime(n+2)^2 - 1)/3.at n=37A024700
- a(n) = (2*n+1)*(11*n+1).at n=21A033575
- Number of partitions satisfying 0 < cn(0,5) + cn(2,5) + cn(3,5).at n=33A039899
- Numbers m such that m^2 can be obtained from m by inserting an internal block of (contiguous) digits.at n=17A045953
- Numbers k such that k^2 can be obtained from k by inserting a block of digits.at n=24A046838
- Numbers k such that k | sigma_7(k).at n=43A055711
- Successive rows of a triangle, the columns of which are generalized Fibonacci sequences S(j).at n=56A058294
- Triangle with a(n,n)=1, a(n,k)=(n-1)*a(n-1,k)+a(n-2,k) for n>k.at n=37A062323
- a(n) = (2*n-1)*(n^2 -n +2)/2.at n=21A063488
- Number of squares (of another matrix) in M_2(n) - the ring of 2 X 2 matrices over Z_n.at n=23A068197
- a(n) is the largest number such that all of a(n)'s length-n substrings are distinct and divisible by 86.at n=3A093286
- Triangle read by rows. Let S(k) be the sequence defined by F(0)=0, F(1)=1, F(n-1) + (n+k)*F(n) = F(n+1). E.g. S(0) = 0, 1, 1, 3, 10, 43, 225, 1393, 9976, 81201, ... Then S(0), S(1), S(2), ... are written vertically, next to each other, with the initial term of each on the next row down.at n=28A102472
- Triangle read by rows. Let S(k) be the sequence defined by F(0)=0, F(1)=1, F(n-1) + (n+k)*F(n) = F(n+1). E.g. S(0) = 0,1,1,3,10,43,225,1393,9976,81201, ... Then S(0), S(1), S(2), ... are written next to each other, vertically, with the initial term of each on the next row down. The order of the terms in the rows are then reversed.at n=35A102473