6427
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
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 6428
- 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
- 6426
- Möbius Function
- -1
- Radical
- 6427
- 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
- 75
- 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
- 836
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Where the prime race among 5k+1, ..., 5k+4 changes leader.at n=36A007353
- 6-dimensional centered tetrahedral numbers.at n=8A008500
- Pisot sequence T(5,21), a(n) = floor( a(n-1)^2/a(n-2) ).at n=5A010925
- a(n) = 4*a(n-1) + a(n-2) - a(n-3) - a(n-5).at n=5A019992
- Pisot sequence E(4,10).at n=8A020709
- Primes that remain prime through 2 iterations of the function f(x) = 5x + 8.at n=44A023255
- Primes that remain prime through 3 iterations of function f(x) = 5x + 8.at n=15A023286
- n written in fractional base 8/6.at n=31A024648
- 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 79.at n=19A031577
- Number of partitions of n with equal number of parts congruent to each of 0 and 1 (mod 4).at n=44A035540
- Denominators of continued fraction convergents to sqrt(967).at n=7A042871
- Numbers whose base-5 representation contains exactly two 0's and three 2's.at n=26A045183
- Discriminants of imaginary quadratic fields with class number 9 (negated).at n=26A046006
- Digits d in decimal expansion of n replaced with d^3.at n=43A048390
- Primes resulting from procedure described in A048393.at n=5A048394
- Number of (partially defined) monotone maps from intervals of 1..n to 1..n.at n=6A048775
- Primes p such that number of primes produced according to rules stipulated in Honaker's A048853 is 3.at n=10A050665
- Consider all integer triples (i,j,k), j >= k > 0, with binomial(i+2,3)=j^3+k^3, ordered by increasing i; sequence gives j values.at n=10A054206
- Primes p whose period of reciprocal equals (p-1)/6.at n=41A056211
- a(n) is the least prime p, such that next_prime(2*p) - 2*p = 2*n - 1.at n=17A059846