9815
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 12768
- Proper Divisor Sum (Aliquot Sum)
- 2953
- 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
- 9815
- 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
- 135
- 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
- a(n) = floor( n*(n-1)*(n-2)/22 ).at n=61A011904
- Fibonacci sequence beginning 5, 13.at n=15A022138
- a(n) = n*(29*n + 1)/2.at n=26A022287
- Number of self-avoiding paths with diagonal steps from corner to opposite corner of n X n grid.at n=7A038496
- Number of partitions satisfying 0 < cn(1,5) + cn(4,5).at n=33A039898
- Numbers k such that A055079(k) = 2^k.at n=25A057838
- Positive integers i for which A112049(i) == 8.at n=10A112068
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 1), (-1, 1, -1), (1, -1, 1), (1, 1, 0)}.at n=8A149217
- Number of (n+1)X(1+1) 0..2 arrays with the maximum plus the upper median plus the minimum minus the lower median of every 2X2 subblock equal.at n=4A237060
- Number of (n+1)X(5+1) 0..2 arrays with the maximum plus the upper median plus the minimum minus the lower median of every 2X2 subblock equal.at n=0A237064
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the maximum plus the upper median plus the minimum minus the lower median of every 2X2 subblock equal.at n=10A237067
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the maximum plus the upper median plus the minimum minus the lower median of every 2X2 subblock equal.at n=14A237067
- a(n) = (2*n-1)^2 + 14.at n=49A242412
- 3rd-largest term in n-th row of Stern's diatomic triangle A002487.at n=17A244473
- Number of minimal total dominating sets in the n-path graph.at n=34A302655
- Smallest k such that 6*k*A121940(n)-1 and 6*k*A121940(n)+1 are twin primes.at n=44A329920
- Main diagonal of A332369.at n=14A332370
- Numbers that are the sum of ten fourth powers in exactly nine ways.at n=39A345861
- a(n) is the smallest integer k such that the average deviation of previous terms and k is an integer, where a(n) > a(n - 1) and a(1) = 1.at n=46A370488
- a(n) is the smallest number which can be represented as the sum of n distinct nonzero squares in exactly 2 ways, or -1 if no such number exists.at n=29A374287