3907
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 3908
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 3906
- Möbius Function
- -1
- Radical
- 3907
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 38
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 540
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(n) = round(sqrt( 2*Pi )^n).at n=9A001675
- a(n) = ceiling(sqrt( 2*Pi )^n).at n=9A001698
- Primes of form k^2 + k + 1.at n=21A002383
- a(n) = round(1000*log_2(n)).at n=14A004266
- a(n) = ceiling(1000*log_2(n)).at n=14A004267
- Number of triples (i,j,k) with 1 <= i < j < k <= n and gcd(i,j,k) = 1.at n=30A015616
- Numbers k such that the continued fraction for sqrt(k) has period 54.at n=12A020393
- a(n+1) = a(n) converted to base 6 from base 5 (written in base 10).at n=22A023379
- a(n) = least m such that if r and s in {1/1, 1/2, 1/3, ..., 1/n} satisfy r < s, then r < k/m < (k+3)/m < s for some integer k.at n=32A024843
- Coordination sequence T2 for Zeolite Code IFR.at n=44A024983
- Product of n with 666 is palindromic.at n=31A030094
- Primes p such that 666p is palindromic.at n=2A030095
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 61.at n=15A031559
- Upper prime of a difference of 18 between consecutive primes.at n=10A031937
- Coordination sequence T6 for Zeolite Code SFF.at n=41A038432
- Numbers k such that the string 0,7 occurs in the base 10 representation of k but not of k-1.at n=41A044339
- Discriminants of imaginary quadratic fields with class number 7 (negated).at n=27A046004
- Primes p such that p+4 and p+12 are also prime.at n=32A046137
- Array A read by diagonals; n-th difference of (A(k,n), A(k,n-1),..., A(k,0)) is (k+2)^(n-1), for n=1,2,3,...; k=0,1,2,...at n=38A047848
- a(n) = (5^n + 3)/4.at n=6A047850