6565
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 8568
- Proper Divisor Sum (Aliquot Sum)
- 2003
- 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
- 4800
- Möbius Function
- -1
- Radical
- 6565
- 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
- 75
- 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
- Expansion of 1/((1-x)^3 (1-x^2)^2 (1-x^3) (1-x^4)).at n=18A002626
- Numbers that are the sum of 7 positive 7th powers.at n=21A003374
- Numbers that are the sum of 5 nonzero 8th powers.at n=6A003383
- Numbers that are the sum of at most 5 nonzero 8th powers.at n=25A004878
- Numbers that are the sum of at most 6 nonzero 8th powers.at n=32A004879
- Numbers that are the sum of at most 7 nonzero 8th powers.at n=40A004880
- Numbers that are the sum of at most 8 nonzero 8th powers.at n=49A004881
- a(2n-1) = n*a(2n-2), a(2n) = n*a(2n-1) + 1.at n=8A007876
- Molien series of 4-dimensional representation of u.g.g.r. #9.at n=12A013977
- Molien series of 4-dimensional representation of u.g.g.r. #8.at n=24A013978
- a(n) = [ 3rd elementary symmetric function of {log(k)} ], k = 2,3,...,n.at n=14A025203
- Numbers that are the sum of 2 nonzero squares in exactly 4 ways.at n=34A025287
- Numbers that are the sum of 2 nonzero squares in 4 or more ways.at n=35A025295
- Numbers that are the sum of 2 distinct nonzero squares in exactly 4 ways.at n=34A025305
- Numbers that are the sum of 2 distinct nonzero squares in 4 or more ways.at n=35A025314
- Number of partitions of n into parts not of the form 23k, 23k+2 or 23k-2. Also number of partitions with 1 part of size 1 and differences between parts at distance 10 are greater than 1.at n=36A035990
- Numbers having three 0's in base 9.at n=11A043455
- Numbers whose base-4 representation contains exactly four 1's and three 2's.at n=15A045108
- Sum of remainders when n-th prime is divided by all preceding integers.at n=43A050482
- a(n) = n^4+4 = (n^2-2*n+2)*(n^2+2*n+2) = ((n-1)^2+1)*((n+1)^2+1).at n=9A057781