6949
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 6950
- 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
- 6948
- Möbius Function
- -1
- Radical
- 6949
- 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
- 106
- 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
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 892
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers that are the sum of 10 positive 7th powers.at n=33A003377
- Numbers k for which 10k+1, 10k+3, 10k+7 and 10k+9 are primes.at n=28A007811
- a(n) = floor( n*(n-1)*(n-2)/14 ).at n=47A011896
- Quadruples of different integers from [ 1,n ] with no global factor.at n=21A015622
- Quadruples of different integers from [ 2,n ] with no global factor.at n=21A015627
- Numbers k such that the continued fraction for sqrt(k) has period 17.at n=38A020356
- Number of alternating compositions, i.e., compositions with alternating increases and decreases, starting with either an increase or a decrease.at n=20A025047
- Primes with property that when squared all even digits occur together and all odd digits occur together.at n=41A030480
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 11.at n=6A031599
- Primes that do not contain any other prime as a proper substring.at n=42A033274
- Number of partitions satisfying cn(0,5) <= cn(2,5) and cn(0,5) <= cn(3,5).at n=33A039838
- Primes whose sum of digits is the perfect number 28.at n=9A048517
- Primes whose digits are composite; primes having only {4, 6, 8, 9} as digits.at n=12A051416
- Primes having only 0,4,6,8,9 as digits.at n=19A061372
- Let p(k) denote k-th prime; consider solutions (n,m) of the Diophantine system {p(p(n)+1)-p(p(n))=2, p(p(n))-6.p(p(m))=-1} (*); sequence gives values of m.at n=23A065511
- Numbers n such that n, 10*n+1, 10*n+3, 10*n+7 and 10*n+9 are all primes.at n=1A067267
- Minimal set of prime-strings in base 10.at n=15A071062
- a(n) is the smallest index m such that Sum_{k=2..m} 1/PrimePi(k) >= n, where PrimePi()=A000720().at n=34A074633
- First column of triangle A082737.at n=42A082739
- Diagonal of A088262.at n=19A088263