8969
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 32
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 8970
- 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
- 8968
- Möbius Function
- -1
- Radical
- 8969
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 52
- 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
- yes
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1115
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Percolation series for directed b.c.c. lattice.at n=18A006838
- Numbers n such that n, 2n+1, and 4n+3 all prime.at n=39A007700
- Let q_k=p(p+2) be product of k-th pair of twin primes; sequence gives values of p such that (q_k)^2 > q_{k-i}q_{k+i} for all 1 <= i <= k-1.at n=45A021005
- 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+4)/m < s for some integer k.at n=31A024847
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 50 ones.at n=33A031818
- Start of a string of exactly 2 consecutive (but disjoint) pairs of twin primes.at n=22A035790
- Consider the trajectory of n under the iteration of a map which sends x to 3x - sigma(x) if this is >= 0; otherwise the iteration stops. The sequence gives values of n which eventually reach 0.at n=10A037159
- Numerators of continued fraction convergents to sqrt(569).at n=5A042090
- Primes for which only two iterations of 'Prime plus its digit sum equals a prime' are possible.at n=40A048524
- Primes whose digits are composite; primes having only {4, 6, 8, 9} as digits.at n=17A051416
- Primes having only {0, 6, 8, 9} as digits.at n=13A053580
- First of four consecutive primes that comprise two sets of twin primes.at n=34A053778
- Greatest prime factor of n^n + (n+1)^(n+1).at n=10A056790
- Primes p such that x^59 = 2 has no solution mod p.at n=19A059312
- Initial primes of Cunningham chains of first type with length exactly 3. Primes in A059453 that survive as primes just two "2p+1 iterations", forming chains of exactly 3 terms.at n=21A059762
- Primes p such that |p - q| is a square, where q is the reversal of p.at n=31A059798
- Primes having only 0,4,6,8,9 as digits.at n=28A061372
- Sum of digits = 8 times number of digits.at n=30A061425
- Primes related to the nondecreasing subsequence of A007605 (sums of digits of primes).at n=37A067954
- a(1) = 2; for n > 1, a(n) is the smallest prime > a(n-1) such that each successive digit in the concatenation of terms (that does not follow 9) is greater than the previous digit.at n=10A068827