9147
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 12200
- Proper Divisor Sum (Aliquot Sum)
- 3053
- 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
- 6096
- Möbius Function
- 1
- Radical
- 9147
- 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
- 65
- 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
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 31.at n=35A031529
- Sum of first n primes of form 4k-1.at n=44A038347
- Number of primitive (aperiodic) reversible strings with n beads using exactly three different colors.at n=8A056319
- Integers n > 7059 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 7059.at n=21A063058
- Indices of squares (of primes) in the semiprimes.at n=43A128301
- 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, -1), (-1, -1, 0), (-1, 1, 0), (1, -1, 1), (1, 0, 0)}.at n=10A148180
- Partial sums of A160120.at n=33A162778
- Triangle T(n, k) read by rows giving number of non-equivalent ways to choose k points in an equilateral triangle grid of side n.at n=46A231655
- Triangle T(n, k) read by rows giving number of non-equivalent ways to choose k points in an equilateral triangle grid of side n.at n=55A231655
- a(n) = Sum_{i=0..n} digsum_5(i)^4, where digsum_5(i) = A053824(i).at n=21A231671
- a(n) = n-1 for n <= 2; thereafter a(n) = A238824(n-2) + A238832(n-1).at n=13A238833
- The number of NE partitions of n (see Comments).at n=32A239329
- Number of (n+2) X (6+2) 0..3 arrays with every 3 X 3 subblock row and column sum not equal to 0 3 5 6 or 7 and every 3 X 3 diagonal and antidiagonal sum equal to 0 3 5 6 or 7.at n=18A252252
- Sum of the sixth largest parts in the partitions of n into 7 parts.at n=43A308928