4971
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 6632
- Proper Divisor Sum (Aliquot Sum)
- 1661
- 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
- 3312
- Möbius Function
- 1
- Radical
- 4971
- 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
- 72
- 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
- Coordination sequence for 5-dimensional lonsdaleite.at n=9A008525
- a(n) = least m such that if r and s in {1/1, 1/3, 1/5, ..., 1/(2n-1)} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.at n=38A024834
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (F(2), F(3), F(4), ...), t = A000201 (lower Wythoff sequence).at n=19A025107
- Number of partitions of n into an odd number of parts, the least being 4; also, a(n+4) = number of partitions of n into an even number of parts, each >=4.at n=62A027190
- 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 46.at n=25A031544
- a(n) = 4*n^2 - 6*n + 3.at n=35A054569
- Column 7 of triangle A055898.at n=4A055903
- Numbers n such that 2^n in base 3 has same number of 2's as 2^(n+1) in base 3 and 2^n and 2^(n+1) have the same number of digits in base 3.at n=45A056736
- C(n+3)=2*C(n), where C(n) is Cototient(n) := n - phi(n) (A051953).at n=32A063480
- Sum of the remainders when the n-th triangular number is divided by all smaller triangular numbers > 1.at n=41A072524
- a(n+4) = floor( ( a(n) + 2*a(n+1) + 3*a(n+2) + 4*a(n+3) )/5 ), with a(0), a(1), a(2), a(3) equal to 0, 1, 2, 3.at n=23A074733
- Right-truncatable semiprimes.at n=45A085733
- Abs(*+-) n Sequence.at n=36A119518
- p^2-p+1 central polygonal numbers with prime indices A002061(prime(n)).at n=19A119959
- Semiprimes s such that s-/+2 are primes.at n=29A125215
- Numbers such that the sum of the factorials of the digits of the fifth power is a square.at n=7A126078
- Numbers k that divide 3^((k-1)/2) - 2^((k-1)/2) - 1.at n=36A130061
- Numbers k such that 2^(2*k - 1) - 1 is prime.at n=20A138576
- Composites of form n^2 + n + 1.at n=45A174969
- Numbers of the form k^2+k+1 that are the product of two distinct primes.at n=31A176069