3989
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 29
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 3990
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 3988
- Möbius Function
- -1
- Radical
- 3989
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 51
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 550
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- 6th power of rooted tree enumerator; number of linear forests of 6 rooted trees.at n=6A000395
- Spiral sieve using Fibonacci numbers.at n=17A005620
- Number of Q-graphs with 2n edges.at n=6A007171
- Coordination sequence T1 for Zeolite Code AWW.at n=45A008045
- Coordination sequence T6 for Zeolite Code MFI.at n=40A008169
- a(n) = floor(n*(n-1)*(n-2)/9).at n=34A011891
- Numbers k such that the continued fraction for sqrt(k) has period 21.at n=26A020360
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (1, p(1), p(2), ...), t = (composite numbers).at n=22A024480
- a(n) = Sum_{k=0..n} binomial(n,k)*binomial(2*k,k).at n=6A026375
- a(n) = T(n,[ n/2 ]), where T is the array in A026374.at n=11A026380
- Self-convolution of array T given by A026374.at n=6A026946
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted then there are a pair of central terms both equal to 4.at n=31A031417
- Lower prime of a difference of 12 between consecutive primes.at n=39A031930
- Primes of form x^2+89*y^2.at n=20A033257
- Number of partitions of n into parts not of form 4k+2, 24k, 24k+3 or 24k-3. Also number of partitions in which no odd part is repeated, with 1 part of size less than or equal to 2 and where differences between parts at distance 5 are greater than 1 when the smallest part is odd and greater than 2 when the smallest part is even.at n=45A036030
- Number of partitions satisfying cn(1,5) < cn(2,5) + cn(3,5) and cn(4,5) < cn(2,5) + cn(3,5).at n=32A039888
- Denominators of continued fraction convergents to sqrt(613).at n=10A042177
- Numbers whose base-5 representation contains exactly three 1's and two 4's.at n=23A045261
- a(n) = A047080(2*n+1, n+2).at n=7A047088
- Primes p such that number of primes produced according to rules stipulated in Honaker's A048853 is 5.at n=43A050667