3942
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 8880
- Proper Divisor Sum (Aliquot Sum)
- 4938
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 1296
- Möbius Function
- 0
- Radical
- 438
- Omega Function (Ω)
- 5
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 25
- 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
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Number of perfect matchings (or domino tilings) in D_4 X P_(n-1).at n=9A003757
- Coordination sequence T7 for Zeolite Code MFS.at n=39A008179
- Coordination sequence T2 for Zeolite Code NAT.at n=42A008204
- Coordination sequence T1 for Cordierite.at n=38A008251
- Apply partial sum operator thrice to primes.at n=12A014150
- Numbers k such that k divides 2^(k+1) - 2.at n=23A014741
- Positive integers n such that n | (2^n + n/2 - 1).at n=21A015942
- Expansion of 1/((1-x)*(1-2*x)*(1-7*x)*(1-11*x)).at n=3A021244
- a(n) = Sum_{k=1..n} (n-k) * floor(n/k).at n=35A024920
- Concatenation of n and n + 3.at n=38A032608
- Base 6 digits are, in order, the first n terms of the periodic sequence with initial period 3,0,1.at n=4A037648
- Numerators of continued fraction convergents to sqrt(47).at n=6A041080
- Numerators of continued fraction convergents to sqrt(330).at n=2A041622
- Numbers whose base-5 representation contains exactly three 1's and two 2's.at n=24A045231
- Numbers n such that 2^n in base 3 has same number of 2's as 2^(n+1) in base 3 and 2^n and 2^(n+1) have the same number of digits in base 3.at n=37A056736
- From solution to a Picard-Fuchs equation.at n=5A061401
- Positive numbers whose product of digits is 12 times their sum.at n=33A062045
- Write 1, 2, 3, 4, ... counterclockwise in a hexagonal spiral around 0 starting left down, then a(n) is the sequence found by reading from 0 in the vertical upward direction.at n=18A063436
- Numbers k such that Euler phi(k) / Carmichael lambda(k) = 18.at n=19A066697
- Numbers k such that phi(k) is a perfect biquadrate.at n=42A078164