6131
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 6132
- 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
- 6130
- Möbius Function
- -1
- Radical
- 6131
- 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
- 155
- 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
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- yes
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 799
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers n such that n, 2n+1, and 4n+3 all prime.at n=33A007700
- Number of 5-tuples of different integers from [ 1,n ] with no global factor.at n=16A015640
- Numbers k such that the continued fraction for sqrt(k) has period 50.at n=41A020389
- Number of compositions of n into 6 ordered relatively prime parts.at n=12A023031
- Least k such that first k terms of A022300 contain n more 2's than 1's.at n=2A025515
- Primes p such that digits of p appear in p^2 and p^3.at n=34A030085
- Cube root of A030690.at n=47A030691
- 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 77.at n=13A031575
- Numbers whose base-4 representation contains exactly two 1's and four 3's.at n=26A045123
- Primes p such that p+2 and 2p+1 are also prime.at n=44A045536
- Primes with first digit 6.at n=33A045712
- Let (p1,p2), (p3,p4) be pairs of twin primes with p1*p2=p3+p4-1; sequence gives values of p1.at n=13A047976
- Prime number spiral (clockwise, South spoke).at n=14A054566
- Primes q of the form q = 10p + 1, where p is also prime.at n=27A055781
- Initial primes of Cunningham chains of first type with length exactly 3. Primes in A059453 that survive as primes just two "2p+1 iterations", forming chains of exactly 3 terms.at n=17A059762
- Record-setting values of q(n), the minimal prime q such that n(q+1)-1 is a prime p (i.e., q(n) > q(j) for all 0 < j < n).at n=7A062256
- a(1) = 61 ( the smallest prime beginning with 6) and then the smallest prime with leading digits containing a(n-1).at n=2A068850
- Primes > 100 in which every substring of length 2 is also prime.at n=37A069488
- Primes > 1000 in which every substring of length 3 is also prime.at n=41A069489
- Primes > 1000 in which every substring of lengths 2 and 3 are also prime.at n=3A069490