8627
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 8628
- 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
- 8626
- Möbius Function
- -1
- Radical
- 8627
- 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
- no
- 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
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1074
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- G.f.: 1/((1-x)*(1-x^2)*(1-x^3)^2*(1-x^4)*(1-x^5)).at n=43A003402
- Coordination sequence for Ni2In, Position Ni1 and In.at n=28A009941
- Primes that remain prime through 3 iterations of function f(x) = 9x + 4.at n=22A023297
- 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 91.at n=28A031589
- Discriminants of imaginary quadratic fields with class number 21 (negated).at n=26A046018
- Least prime in A001359 (lesser of twin primes) such that the distance (A053319) to the next twin is 6*n.at n=31A052350
- Number of asymmetric mobiles (circular rooted trees) with n nodes and 8 leaves.at n=5A055369
- Primes of the form 4*k^2 + 163.at n=39A057604
- Lesser of irregular twin primes.at n=28A060012
- Numbers k such that sigma(k+2) - sigma(k) = prime(k+1) - prime(k).at n=27A067062
- Smallest member of a pair of consecutive twin prime pairs that have exactly n primes between them.at n=22A089637
- Arithmetic derivative of n-th partition number.at n=34A096371
- Primes of the form pq - 6, where p and q are consecutive primes.at n=11A099775
- Primes from merging of 4 successive digits in decimal expansion of e.at n=17A104845
- Largest of five consecutive primes the sum of the digits of each of which is prime.at n=25A106717
- a(n) = sum(k=0,n,B_k*A000629(k)*A000629(n-k)) where B_k is the k-th Bernoulli number.at n=6A111154
- Least prime p for which Mertens's function M(p) = n.at n=29A123172
- a(n) = p, the lesser of twin primes (p, q=p+2) such that p*q + p + q is prime.at n=39A128550
- Number of minimally strongly connected digraphs on n vertices, up to isomorphism.at n=8A130756
- Number of conjugate-congruent partitions of n.at n=38A137438