3691
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
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 3692
- 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
- 3690
- Möbius Function
- -1
- Radical
- 3691
- 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
- 69
- 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
- 515
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(0) = 1, a(1) = 5, a(n) = 4*a(n-1) - a(n-2).at n=6A001834
- a(2*n) = a(2*n-1) + a(2*n-2), a(2*n+1) = 2*a(2*n) + a(2*n-1); a(0) = a(1) = 1.at n=13A002531
- Coordination sequence T1 for Zeolite Code MAZ.at n=42A008144
- Coordination sequence T2 for Zeolite Code AHT.at n=41A009867
- Values of k at which the period of the continued fraction for sqrt(k) sets a new record.at n=36A013645
- Primes that remain prime through 2 iterations of function f(x) = 9x + 4.at n=45A023266
- Primes that remain prime through 3 iterations of function f(x) = 5x + 6.at n=18A023285
- a(n) is the least odd prime p such that the maximum run length of consecutive quadratic residues modulo p is n.at n=14A025046
- 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 59.at n=21A031557
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 50 ones.at n=2A031818
- Upper prime of a difference of 14 between consecutive primes.at n=19A031933
- Take list of squares, move left digit of each term to end of previous term.at n=38A032760
- Primes of the form x^2+74*y^2.at n=25A033248
- Write 1,2,... in a clockwise spiral; sequence gives numbers on positive x axis.at n=30A033951
- Decimal part of a(n)^(1/11) starts with n (11th powers excluded).at n=11A034066
- a(0)=2; a(n) is the smallest k > a(n-1) such that the fractional part of k^(1/11) starts with n.at n=11A034076
- a(n)=(s(n)+4)/9, where s(n)=n-th base 9 palindrome that starts with 5.at n=25A043076
- Numbers m such that string 9,1 occurs in the base 10 representation of m but not of m+1.at n=39A044804
- Discriminants of imaginary quadratic fields with class number 13 (negated).at n=16A046010
- Sequence of 2 Pythagorean triangles, each with a leg and hypotenuse prime. The leg of the second triangle is the hypotenuse of the first.at n=17A048270