6694
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 10044
- Proper Divisor Sum (Aliquot Sum)
- 3350
- 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
- 3346
- Möbius Function
- 1
- Radical
- 6694
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 93
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Numbers that are the sum of 9 positive 7th powers.at n=28A003376
- From the graph reconstruction problem.at n=6A006655
- Coordination sequence for Cr3Si, Cr position.at n=21A009928
- sec(tan(x)+arcsin(x))=1+4/2!*x^2+104/4!*x^4+6694/6!*x^6+801048/8!*x^8...at n=3A012958
- Values of k at which the period of the continued fraction for sqrt(k) sets a new record.at n=44A013645
- 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 80.at n=19A031578
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 78 ones.at n=0A031846
- Numbers k such that the sum of the first k primes is a square.at n=2A033997
- a() = 1,3,... [ A037257 ], differences = 2,... [ A037258 ] and 2nd differences [ A037259 ] are disjoint and monotonic; adjoin next free number to 2nd differences unless it would produce a duplicate in which case ignore.at n=29A037257
- Numbers n such that there are equal numbers of 0's and 1's in first n digits of binary representation of Pi.at n=38A039624
- a(1) = 1, a(m+1) = 2*Sum_{k=1..floor((m+1)/2)} a(k).at n=51A039722
- Geometric mean of the digits = 6. In other words, the product of the digits is = 6^k where k is the number of digits.at n=38A061429
- G.f. A(x) satisfies: A(A(x)) = x*(1+2*x)^2.at n=8A097090
- n-th Fibonacci number minus n-th prime number.at n=19A100700
- Semiprimes with semiprime digits (digits 4, 6, 9 only).at n=25A107342
- Dying rabbits: a(n) = Fibonacci(n) for n <= 12; for n >= 13, a(n) = a(n-1) + a(n-2) - a(n-13).at n=20A107358
- Conjectured smallest Sierpiński numbers of the second kind S, base b=2,3,4,5,..., where S*b^n+1 is composite for all n>=1 and gcd(S+1, b-1) = 1.at n=20A123159
- Expansion of g.f. x^3*(1 - x)/(1 - x - x^2 - x^3 - x^4 - x^5).at n=17A124312
- a(n) = Frobenius number for 3 successive primes = F[p(n), p(n+1), p(n+2)].at n=44A138989
- Number of nonprime parts in the last section of the set of partitions of n.at n=29A144121