3918
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
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 7848
- Proper Divisor Sum (Aliquot Sum)
- 3930
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 1304
- Möbius Function
- -1
- Radical
- 3918
- 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
- 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
- yes
- Odd
- no
Appears in sequences
- Coordination sequence T1 for Zeolite Code CHA.at n=48A008066
- Coordination sequence T6 for Zeolite Code EUO.at n=39A008101
- Coordination sequence T1 for Zeolite Code NAT.at n=42A008203
- Coordination sequence T3 for Zeolite Code -ROG.at n=47A009861
- Coordination sequence for sigma-CrFe, Position Xd.at n=16A009959
- Coordination sequence T2 for Zeolite Code SAT.at n=45A027374
- Numbers having three 3's in base 9.at n=28A043467
- Partial sums of A045954.at n=42A045964
- a(n) = a(n-1) + a(m) for n >= 4, where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 2, and a(3) = 1.at n=43A050041
- Starting positions of strings of 2 3's in the decimal expansion of Pi.at n=29A050222
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 16.at n=36A051981
- Expansion of 4th power of continued fraction 1/ ( 1+q/ ( 1+q^2/ ( 1+q^3/ ( 1+q^4/... )))).at n=40A055103
- At these values of k the first, 2nd and 3rd cyclotomic polynomials all give prime numbers.at n=21A070020
- Squarefree numbers sandwiched between a pair of twin primes.at n=30A070195
- Interprimes which are of the form s*prime, s=6.at n=34A075281
- Engel expansion for (positive) constant defined in A078756.at n=6A080230
- a(n) = n + (n-1)^2 + (n+1)^2.at n=44A096376
- Least k such that decimal representation of k*n contains only digits 0 and 6.at n=16A096685
- a(n) = digit reversal of A103741(n).at n=29A103763
- Number of partitions of n into parts but with two kinds of parts of sizes 1 to 10.at n=15A103929