3939
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 5712
- Proper Divisor Sum (Aliquot Sum)
- 1773
- 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
- 2400
- Möbius Function
- -1
- Radical
- 3939
- 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
- 25
- 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
- Doublets: base-10 representation is the juxtaposition of two identical strings.at n=38A020338
- a(1) = 3; a(n+1) = a(n)-th nonprime, where nonprimes begin at 1.at n=27A025004
- Coordination sequence T4 for Zeolite Code ITE.at n=43A027372
- Numbers whose square contains no loops in its digits (assumes 1, 2, 3, 5, 7 have no loops and 0, 4, 6, 8, 9 do).at n=43A034905
- Base 6 digits are, in order, the first n terms of the periodic sequence with initial period 3,0,1,2.at n=4A037760
- Numbers whose base-5 representation contains exactly three 1's and two 2's.at n=23A045231
- Composite numbers whose 3 prime factors are distinct in length.at n=39A046443
- Numbers whose consecutive digits differ by 6.at n=26A048408
- Nonprime numbers n such that n and n-reversed (<>n and no leading zeros) have the same number of prime factors and these prime factors (palindromes allowed here) are also reversals of each other.at n=49A050702
- Central column of arrays in A057027 and A057028.at n=44A057029
- Number of ways to cover (without overlapping) a ring lattice (necklace) of n sites with molecules that are 6 sites wide.at n=32A058367
- a(n) = Sum_{d|n} d*prime(d).at n=30A061150
- Composites for which the row of the prime-composite array (A063173) includes the leftmost element of both a zero-only antidiagonal and a zero-only diagonal(A067681).at n=31A063176
- Product of n-th prime number and n-th composite number.at n=25A067563
- Smallest multiple of n not equal to n ending in (digits of) n.at n=38A075559
- Numbers k such that 2 + 2^k + 3^k is prime.at n=9A076513
- Leading diagonal of A083173.at n=25A083174
- a(n) = the least integer of the form [prime(n+1)+prime(n+2)+...+prime(n+k)]/prime(n).at n=51A086448
- Structured truncated tetrahedral numbers.at n=12A100156
- Expansion of (1+t^3)^2/((1-t)*(1-t^2)^2*(1-t^4)).at n=44A106607