6595
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7920
- Proper Divisor Sum (Aliquot Sum)
- 1325
- 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
- 5272
- Möbius Function
- 1
- Radical
- 6595
- 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
- 124
- 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 period 60.at n=28A020399
- T(2n-1,n-1), T given by A026681.at n=6A026685
- T(n,[ n/2 ]), T given by A026681.at n=13A026687
- Average of four successive primes squared, (prime(n)^2 + prime(n+1)^2 + prime(n+2)^2 + prime(n+3)^2)/4, n>=2.at n=19A075894
- Positions of A080299 in A014486.at n=22A080298
- Triangle, read by rows, where row n forms a polynomial in y=3*k that generates diagonal n as k=0,1,2,... for n>=0; thus T(n,k) = Sum_{j=0..n-k} T(n-k,j)*(3*k)^j, with T(n,0)=T(n,n)=1.at n=23A113716
- Column 2 of triangle A113716, in which row n forms a polynomial in y=3*k that generates diagonal n as k=0,1,2,... for n>=0.at n=4A113718
- Numbers n such that 379*10^n+9 is a ("Google") probable prime.at n=17A159264
- Numbers congruent to 3 in the structure (or curve) of A211000.at n=32A211002
- Number of (n+1)X(n+1) -6..6 symmetric matrices with every 2X2 subblock having sum zero and one, two or three distinct values.at n=5A211257
- Composite squarefree numbers n such that p + tau(n) divides n - phi(n), where p are the prime factors of n, tau(n) = A000005(n) and phi(n) = A000010(n).at n=35A229324
- Sum T(n,k) over all partitions lambda of n into k distinct parts of Product_{i:lambda} prime(i); triangle T(n,k), n>=0, 0<=k<=A003056(n), read by rows.at n=59A258323
- Sum over all partitions lambda of n into 4 distinct parts of Product_{i:lambda} prime(i).at n=5A258359
- a(n) = [x^n] Product_{k=1..n} (1+x^k)^2 / x^k.at n=9A258797
- Partial sums of A080715.at n=25A268403
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 395", based on the 5-celled von Neumann neighborhood.at n=21A271687
- a(n) is the index of the first occurrence of n in A166006.at n=4A278737
- G.f.: Product_{k>=1} (1 + x^(k*(k+1))) / (1 - x^k).at n=27A280423
- a(n) is the position of the first occurrence of n^3 in the concatenation of the positive integers in decimal representation.at n=20A290787
- Solution of the complementary equation a(n) = 2*a(n-1) - a(n-2) + b(n-1) -1, where a(0) = 1, a(1) = 2, b(0) = 3, and (a(n)) and (b(n)) are increasing complementary sequences.at n=31A294867