3969
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 15
- Divisor Sum
- 6897
- Proper Divisor Sum (Aliquot Sum)
- 2928
- 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
- 2268
- Möbius Function
- 0
- Radical
- 21
- Omega Function (Ω)
- 6
- 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
- yes
- 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
- 144
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- yes
- Achilles Number
- no
- Perfect Power
- yes
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Squares that are not the sum of 2 nonzero squares.at n=37A000548
- Numbers of the form 3^i*7^j with i, j >= 0.at n=22A003594
- Powers of 3 written in base 12. (Next term contains a non-decimal character.)at n=8A004666
- Product of the proper divisors of n.at n=62A007956
- Expansion of e.g.f.: log(1 + exp(x)*x).at n=9A009306
- "Pascal sweep" for k=6: draw a horizontal line through the 1 at C(k,0) in Pascal's triangle; rotate this line and record the sum of the numbers on it (excluding the initial 1).at n=59A009475
- Number of partitions of 2*n into at most 4 parts.at n=39A014126
- Numbers k such that k divides 4^k - 1.at n=29A014945
- Integers k such that k divides 22^k - 1.at n=38A014959
- Odd numbers k that divide 25^k - 1.at n=37A014962
- Numbers k such that k | 5^k + 1.at n=27A015951
- Odd squares: a(n) = (2n+1)^2. Also centered octagonal numbers.at n=31A016754
- a(n) = (3*n)^2.at n=21A016766
- a(n) = (4n + 3)^2.at n=15A016838
- a(n) = (5*n + 3)^2.at n=12A016886
- a(n) = (6*n+3)^2.at n=10A016946
- a(n) = (7*n)^2.at n=9A016982
- a(n) = (8*n + 7)^2.at n=7A017150
- a(n) = (9*n)^2.at n=7A017162
- a(n) = (10*n + 3)^2.at n=6A017306