13847
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 14136
- Proper Divisor Sum (Aliquot Sum)
- 289
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13560
- Möbius Function
- 1
- Radical
- 13847
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 89
- 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
- a(n) = [ 1/(2*t(n+1) - t(n) - t(n+2)) ], where t(n) = tan(Pi/2 - 1/n) satisfies n-1 < t(n) < n for all n >= 1.at n=19A024817
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 19 ones.at n=8A031787
- Upper members of a "good pair" of the form (k, 2*k +- 1).at n=43A046862
- a(n+1)=a(n)+a^(n), where the addition is in base 11 and where a^(n) is obtained from a(n) by replacing each digit with its multiplicative inverse modulo 11. Zero digits, if any, are deleted.at n=12A053697
- Expansion of (7 +4*x -5*x^2 -7*x^3) / ((1-x)*(1-x^2-x^3)).at n=27A103485
- Composite numbers generated by the Euler polynomial x^2 + x + 41.at n=17A145292
- Numbers n with property that n^2 is a concatenation of three 3-digit primes.at n=12A153139
- a(n) = 9*n^2 + 39*n + 83.at n=37A210527
- Semiprimes generated by the Euler polynomial x^2 + x + 41.at n=17A228183
- a(n) = (2n-2)^3 + (2n-2) - 1.at n=12A255877
- Number of (n+1) X (3+1) 0..1 arrays with every 2 X 2 subblock ne-sw antidiagonal difference nondecreasing horizontally and nw+se diagonal sum nondecreasing vertically.at n=8A258549
- Integers k such that 3*k!!! - 1 is prime where k!!! is A007661(k).at n=49A271396
- a(n) = n * Sum_{d|n} sigma(d)^3 / d.at n=22A344043
- G.f.: Product_{k>=1} (1 + x^(3*k^2)) / (1 - x^k).at n=32A385010
- G.f. A(x) satisfies A(x) = 1/( 1 - x*(A(x) + A(3*x))/2 ).at n=5A385622