13623
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 19200
- Proper Divisor Sum (Aliquot Sum)
- 5577
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8568
- Möbius Function
- -1
- Radical
- 13623
- 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
- 94
- 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
- Number of conjugacy classes of compact Cartan subgroups in Sp_{2n}(F), where p>n and the p-adic field F contains all r-th roots of unity for all r <= 2n.at n=5A007793
- Numbers n such that 137 * 2^n + 1 is a prime.at n=10A032418
- Numbers n such that sigma(n)=phi(n*bigomega(n)-1).at n=30A067877
- Round(1000*x), where x is the solution to x = 3^(n-x).at n=16A103537
- Odd interprimes divisible by 19.at n=38A126231
- Partial sums of A051941.at n=17A136105
- Numbers which are the sum of 3 cubes of distinct odd primes.at n=38A138853
- Number of 5 X n binary arrays without the pattern 0 1 diagonally, vertically, antidiagonally or horizontally.at n=17A188556
- G.f. A(x) satisfies A(x) = 1 + x / (1 - x * A(x^2)).at n=22A218032
- Number of (n+2)X(1+2) 0..1 arrays with no 3x3 subblock diagonal sum 1 and no antidiagonal sum 2 and no row sum 0 and no column sum 3.at n=9A255794
- T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with no 3x3 subblock diagonal sum 1 and no antidiagonal sum 2 and no row sum 0 and no column sum 3.at n=45A255801
- Bihappy numbers: numbers that reach 1 under iteration of the sum-of-squares-of-two-digits map s_2.at n=44A257795
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 573", based on the 5-celled von Neumann neighborhood.at n=22A272997
- a(0) = 1; for n > 0, a(n) = 1 + Sum_{k = 1..n} 2^k a(floor(log_2(k))).at n=8A297621
- Number of solutions to x^2 + y^2 + z^2 + w^2 <= n^2, where x, y, z, w are positive odd integers.at n=29A349611