3935
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
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 4728
- Proper Divisor Sum (Aliquot Sum)
- 793
- 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
- 3144
- Möbius Function
- 1
- Radical
- 3935
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 100
- 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) = n*(7*n^2 - 1)/6.at n=15A004126
- a(n) = floor(n*phi^10), where phi is the golden ratio, A001622.at n=32A004925
- Coordination sequence T2 for Zeolite Code ATT.at n=45A008042
- Coordination sequence T3 for Zeolite Code NES.at n=40A008207
- Nine iterations of Reverse and Add are needed to reach a palindrome.at n=21A015990
- 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 11.at n=36A031509
- Every run of digits of n in base 4 has length 2.at n=35A033002
- Base-4 palindromes that start with 3.at n=39A043005
- Numbers whose base-4 representation contains exactly two 1's and four 3's.at n=9A045123
- Numbers whose base-5 representation contains exactly three 1's and two 2's.at n=21A045231
- Numbers k such that the Lucas Aurifeuillian primitive part A of Lucas(k) is prime.at n=38A061442
- Numbers which need nine 'Reverse and Add' steps to reach a palindrome.at n=21A065214
- Number of distinct values of multinomial coefficients ( n / (p1, p2, p3, ...) ) where (p1, p2, p3, ...) runs over all partitions of n.at n=34A070289
- Matrix inverse of triangle A063967.at n=38A091698
- Numbers n such that 3^n-2^(n-1) is prime.at n=24A095906
- Number of irregular primes less than or equal to the 10^n-th prime.at n=3A105468
- Positive integers i for which A112049(i) == 6.at n=25A112066
- Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n starting with exactly k consecutive pyramids. A pyramid in a Dyck path is a factor of the form U^j D^j (j>0), starting at the x-axis. Here U=(1,1) and D=(1,-1). This definition differs from the one in A091866.at n=56A127156
- a(n) = pq + pr + qr with p = prime(n), q = prime(n+1), and r = prime(n+2).at n=10A127345
- Composites in A127345.at n=4A127347