3947
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 3948
- 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
- 3946
- Möbius Function
- -1
- Radical
- 3947
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 188
- 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
- yes
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 548
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Boustrophedon transform of triangular numbers 1,1,3,6,10,...at n=7A000718
- Number of partitions into one kind of 1's, two kinds of 2's, and three kinds of 3's.at n=28A002597
- Expansion of e.g.f. 1/(3 - exp(x) - exp(2*x)).at n=4A004700
- Coordination sequence T1 for Zeolite Code BRE.at n=41A008058
- Coordination sequence T4 for Zeolite Code MFI.at n=40A008167
- Coordination sequence T2 for Zeolite Code VET.at n=38A009903
- Coordination sequence T4 for Zeolite Code TER.at n=42A016436
- Number of subsets of { 1, ..., n } containing an A.P. of length 6.at n=15A018791
- a(0)=a(1)=3; thereafter a(n) = a(n-1) + a(n-2) + 1.at n=15A022403
- a(0)=3, a(1)=7; thereafter a(n) = a(n-1) + a(n-2) + 1.at n=14A022406
- Primes that remain prime through 2 iterations of the function f(x) = 2x + 7.at n=39A023244
- a(n) = (d(n)-r(n))/2, where d = A026043 and r is the periodic sequence with fundamental period (1,1,0,0).at n=25A026044
- 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=21A031559
- Lower prime of a difference of 20 between consecutive primes.at n=4A031938
- Concatenation of n and n + 8 or {n,n+8}.at n=38A032613
- Primes that are concatenations of n with n + 8.at n=5A032631
- Position reached by frog in A038027 or 0 if none. A038026(A038027(n)).at n=10A038028
- Numbers whose base-5 representation contains exactly three 1's and two 2's.at n=25A045231
- Discriminants of imaginary quadratic fields with class number 17 (negated).at n=8A046014
- F-primes.at n=37A046872