6671
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7632
- Proper Divisor Sum (Aliquot Sum)
- 961
- 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
- 5712
- Möbius Function
- 1
- Radical
- 6671
- 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
- 181
- 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
- no
- Odd
- yes
Appears in sequences
- Numbers n such that 54*10^n + 1 is prime.at n=11A004203
- Numbers k such that Fib(k) == -13 (mod k).at n=25A023167
- Numbers k such that 221*2^k+1 is prime.at n=28A032487
- Numbers k such that if d,e are consecutive digits of k in base 6, then |d-e| >= 4.at n=41A032988
- Positive numbers having the same set of digits in base 4 and base 9.at n=31A037427
- Number of primes between n*100000 and (n+1)*100000.at n=36A038825
- Denominators of continued fraction convergents to sqrt(374).at n=6A041709
- Numbers whose base-9 representation has exactly 5 runs.at n=18A043634
- Coefficients of the '6th-order' mock theta function sigma(q).at n=49A053271
- a(n) = (9n^2 + 9n + 4)/2.at n=38A062123
- Squarefree n such that the elliptic curve n*y^2 = x^3 - x arising in the "congruent number" problem has rank 3.at n=8A062693
- Numbers n such that the partition function A000041(k) is even and odd the same number of times for 0 <= k <= n.at n=0A098936
- Row sums of triangle A101224, which is related to the Flavius sieve (A000960).at n=19A101105
- a(1) = 335; a(n) is the smallest k > a(n-1) such that k*A002110(n)^30 - 1 is prime.at n=30A119760
- Absolute value of coefficient of X^2 in the characteristic polynomial of the n-th power of the matrix M = {{1,1,1,1,1}, {1,0,0,0,0}, {0,1,0,0,0}, {0,0,1,0,0}, {0,0,0,1,0}}.at n=22A123126
- A007318 * A084938.at n=49A134380
- Pyramid game person numbers that have integer solutions.at n=14A135051
- Beastly fax numbers: numbers containing the fax number of the Beast (667, one more than its regular number) in their decimal expansion.at n=8A138563
- a(n) = (n^3 + 18*n^2 + 17*n + 6)/6.at n=29A143058
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 1), (1, 0, -1), (1, 1, -1), (1, 1, 1)}.at n=7A149752