3219
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 4560
- Proper Divisor Sum (Aliquot Sum)
- 1341
- 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
- 2016
- Möbius Function
- -1
- Radical
- 3219
- 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
- 74
- 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
- a(n) = 1000*log(n) rounded to the nearest integer.at n=24A004241
- a(n) = ceiling(1000*log(n)).at n=24A004242
- a(n) = floor(n*phi^12), where phi is the golden ratio, A001622.at n=10A004927
- Coordination sequence T4 for Zeolite Code AFR.at n=43A008022
- Coordination sequence T4 for Zeolite Code MFI.at n=36A008167
- a(n) = floor( n*(n-1)*(n-2)/23 ).at n=43A011905
- Expansion of 1/(1-x^6-x^7-x^8-x^9-x^10).at n=49A017850
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly five 1's.at n=28A020441
- a(n) = Sum_{k=1..n} floor((n/k)*floor(n/k)).at n=44A024921
- Odd composite numbers n such that the digit sum of n equals digit sum of sum of its prime factors (counted with multiplicity).at n=39A036923
- Growth function (or coordination sequence) of the infinite cubic graph corresponding to the srs net (a(n) = number of nodes at distance n from a fixed node).at n=49A038620
- a(n)=(s(n)+2)/8, where s(n)=n-th base 8 palindrome that starts with 6 (in base 8), written in decimal digits.at n=36A043070
- Numbers k such that the string 6,6 occurs in the base 9 representation of k but not of k-1.at n=39A044311
- Numbers k such that string 1,9 occurs in the base 10 representation of k but not of k-1.at n=36A044351
- Numbers n such that string 1,9 occurs in the base 10 representation of n but not of n+1.at n=36A044732
- Numbers n such that string 2,1 occurs in the base 10 representation of n but not of n+1.at n=35A044734
- A B2-sequence due to Rachel Lewis.at n=42A046185
- List of binary palindromes of even length (written in base 10).at n=50A048701
- Intrinsic 12-palindromes: n is an intrinsic k-palindrome if it is a k-digit palindrome in some base.at n=18A060949
- Numbers k such that sigma(k+1) = 4*phi(k).at n=36A067262