8688
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 30
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 22568
- Proper Divisor Sum (Aliquot Sum)
- 13880
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 2880
- Möbius Function
- 0
- Radical
- 1086
- Omega Function (Ω)
- 6
- Little Omega Function (ω)
- 3
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
- 140
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- a(n) = n*(17*n - 1)/2.at n=32A022274
- a(n) = binomial(n+2, 2) + binomial(n+4, 5).at n=14A027658
- a(n)-th and (a(n)+1)-st primes are the first pair of primes that differ by exactly 2n; a(n) = -1 if no such pair of primes exists.at n=31A038664
- Numbers having three 8's in base 10.at n=14A043523
- Let (u1,u2) be successive untouchable numbers such that phi(u1) = phi(u2); sequence gives values of u2.at n=27A048190
- Digits composite, each digit minus 1 is prime, sum of digits minus 1 is prime, difference of digits (in absolute value) minus 1 is prime.at n=42A058229
- Smallest multiple of n-th prime with all even digits.at n=41A062281
- Index of smallest prime p such that there is a gap of 2^n between p and next prime.at n=5A062531
- Integers n > 7059 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 7059.at n=17A063058
- Values of m such that N=(am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,9.at n=14A064241
- Numbers where A080374 increases.at n=18A080376
- a(n) = 16*(8*prime(n) + 7).at n=18A098823
- Number of partitions of n having nonnegative even rank (the rank of a partition is the largest part minus the number of parts).at n=38A101709
- Numbers k such that 5*10^k + 2*R_k - 1 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=17A103008
- Let M = the 3 X 3 matrix [1 1 1; 3 1 0; 2 0 0]. Perform M^n * [1 0 0] getting (1, 3, 2; 6, 6, 2; 14, 24, 12; 50, 66, 28; ...) which we string together to form the sequence.at n=26A107271
- Numbers n such that every digit of n and n-th prime contains a loop (only digits 0,4,6,8,9 in n and n-th prime).at n=13A107624
- Least positive k such that k * [RSA-200]^n - 1 is prime, where RSA-200 is the 200 decimal digit RSA challenge number A391940(15).at n=37A108375
- Number of binary rooted trees with n nodes and internal path length n.at n=43A108643
- a(n) = (n+1)^2*(n+2)*(5*n^2 + 15*n + 12)/24.at n=7A108676
- On the standard 33-hole cross-shaped peg solitaire board, the number of distinct board positions after n jumps (starting with the center vacant).at n=26A112737