6239
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 6624
- Proper Divisor Sum (Aliquot Sum)
- 385
- 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
- 5856
- Möbius Function
- 1
- Radical
- 6239
- 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
- 49
- 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
- Molien series for Conway group Con.0.at n=36A008925
- If x and y are terms, so is x*y + 9.at n=36A009350
- Least k>1 such that first n terms of Kolakoski sequence A000002 repeat in reverse order beginning at k-th term.at n=42A022295
- a(1) = 2; a(n+1) = a(n)-th composite.at n=29A022450
- 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 77.at n=25A031575
- Numerators of continued fraction convergents to sqrt(77).at n=7A041136
- Numerators of continued fraction convergents to sqrt(693).at n=5A042332
- Numbers having four 4's in base 5.at n=34A043368
- a(n) = prime(n)^2 - 2.at n=21A049001
- a(n) = 9*a(n-1)-a(n-2); a(0)=2, a(1)=9.at n=4A056918
- Numbers k such that floor(Pi*k) is a square.at n=47A061812
- Semiprimes p1*p2 such that p2 mod p1 = 10, with p2 > p1.at n=34A064908
- a(n) = 4*n^2 + 4*n - 1.at n=38A073577
- Greatest squarefree number not exceeding n-th prime power which is not prime.at n=45A081218
- Numbers n such that n 7's followed by n is prime.at n=4A084428
- a(n) = n*(n+5)*(50+45*n+n^2)/24.at n=11A101861
- Indices of primes in sequence defined by A(0) = 17, A(n) = 10*A(n-1) - 33 for n > 0.at n=14A102013
- Composite numbers k such that k+d+1 is prime for all divisors d of k greater than 1.at n=43A120776
- Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a zee 1,1 1,2 2,2 2,3 in any orientation.at n=8A145955
- Number of n X n binary arrays symmetric about the diagonal and under 90-degree rotation with all ones connected only in a zee 1,1 1,2 2,2 2,3 in any orientation.at n=18A145957