6842
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
- 5
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 11232
- Proper Divisor Sum (Aliquot Sum)
- 4390
- 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
- 3100
- Möbius Function
- -1
- Radical
- 6842
- 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
- 57
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) is the number of partitions of n (the partition numbers).at n=31A000041
- Place n equally-spaced points around a circle and join every pair of points by a chord; this divides the circle into a(n) regions.at n=21A006533
- Number of parallelogram polyominoes with n cells (also called staircase polyominoes, although that term is overused).at n=11A006958
- Nine iterations of Reverse and Add are needed to reach a palindrome.at n=44A015990
- Numbers with exactly five distinct base-9 digits.at n=35A031986
- Number of partitions of n into even parts.at n=62A035363
- Nonprime partition numbers.at n=24A038753
- Number of partitions satisfying 0 < cn(1,5) + cn(4,5) + cn(2,5) + cn(3,5).at n=31A039896
- Even partition numbers.at n=14A052001
- Number of ways to partition 2n+1 into positive integers.at n=15A058695
- a(n) = p(P(n)), P = primes (A000040), p = partition numbers (A000041).at n=10A058698
- Coefficients in expansion of Sum_{n >= 1} x^n/(1-x^n)^4.at n=33A059358
- Dimension of the space of weight n cuspidal newforms for Gamma_1( 73 ).at n=31A063346
- Dimension of the space of weight n cuspidal newforms for Gamma_1( 95 ).at n=21A063368
- Number of partitions of n with at least one odd part.at n=31A086543
- Partition numbers of the form 3*k+2.at n=9A087185
- a(n) is the number of partitions of n into parts not greater than A020639(n).at n=30A097359
- a(n) = Sum_{i=1..n} A005235(i).at n=43A097589
- Number of partitions of n into integers not greater than the squarefree kernel of n.at n=30A098715
- Sum of the numbers of unitary divisors of the binomial coefficients C(n,k), k=0..n.at n=35A103445