3927
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 5
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 6912
- Proper Divisor Sum (Aliquot Sum)
- 2985
- 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
- 1920
- Möbius Function
- 1
- Radical
- 3927
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 82
- 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=16A002626
- Tricapped prism numbers.at n=13A005920
- a(n) = 3*a(n-1) + a(n-2), with a(0)=0, a(1)=1.at n=8A006190
- Unexplained difference between two partition generating functions.at n=8A007329
- Unique period lengths of primes mentioned in A007615.at n=49A007498
- a(n) = floor( n*(n-1)*(n-2)/10 ).at n=35A011892
- Orders of cyclotomic polynomials containing a coefficient the absolute value of which is >= 4.at n=21A013592
- Orders of cyclotomic polynomials containing a coefficient the absolute value of which is >= 5.at n=9A013593
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly three 1's.at n=44A013650
- a(n) = n*(9*n-2).at n=21A013656
- Pisot sequences E(3,10), P(3,10).at n=6A020704
- Fibonacci sequence beginning 3, 15.at n=13A022381
- a(n+1) = a(n) converted to base 7 from base 5 (written in base 10).at n=12A023380
- a(n+1) = a(n) converted to base 9 from base 8 (written in base 10).at n=37A023391
- Convolution of natural numbers with Beatty sequence for tau^2 A001950.at n=19A023542
- a(n) = Sum_{i=1..floor((n+1)/4)} a(2*i-1) * a(n-2*i+1), with a(1)=a(2)=1.at n=22A024722
- 7 times triangular numbers: 7*n*(n+1)/2.at n=33A024966
- Coordination sequence T1 for Zeolite Code IFR.at n=44A024982
- Triangular array T read by rows (9-diamondization of Pascal's triangle). Step 1: t(n,k) = sum of 9 entries in diamond-shaped subarray of Pascal's triangle having vertices C(n,k), C(n+4,k+2), C(n+2,k), C(n+2,k+2). Step 2: T(n,k) = t(n,k) - t(0,0) + 1.at n=51A026907
- Triangular array T read by rows (9-diamondization of Pascal's triangle). Step 1: t(n,k) = sum of 9 entries in diamond-shaped subarray of Pascal's triangle having vertices C(n,k), C(n+4,k+2), C(n+2,k), C(n+2,k+2). Step 2: T(n,k) = t(n,k) - t(0,0) + 1.at n=48A026907