8179
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 8180
- 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
- 8178
- Möbius Function
- -1
- Radical
- 8179
- 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
- 65
- 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
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1027
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(n) = 2^n - n.at n=13A000325
- Numbers k such that 6!*(2*k-7)!/(k!*(k-1)!) is an integer.at n=9A004786
- Numbers k such that 7!*(2k-8)!/(k!*(k-1)!) is an integer.at n=10A004787
- n is equal to the number of 1's in all numbers <= n written in base 8.at n=3A014885
- 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 89.at n=26A031587
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 50 ones.at n=27A031818
- G.f. satisfies A(x) = 1 + x*cycle_index(Cyclic(4), A(x)).at n=10A036719
- Denominators of continued fraction convergents to sqrt(125).at n=7A041227
- Primes with first digit 8.at n=36A045714
- Primes p such that number of primes produced according to rules stipulated in Honaker's A048853 is 4.at n=27A050666
- Third term of weak prime quintets: p(m-1)-p(m-2) < p(m)-p(m-1) < p(m+1)-p(m) < p(m+2)-p(m+1).at n=20A054825
- Discriminants of imaginary quadratic fields with class number 25 (negated).at n=14A056987
- Primes -p+2^n with smallest p prime, arising in A057674.at n=12A057674
- Primes of the form 2^p - p where p is prime.at n=2A057678
- Primes p such that x^29 = 2 has no solution mod p.at n=32A059256
- Primes p such that x^47 = 2 has no solution mod p.at n=23A059257
- Primes p such that p^11 reversed is also prime.at n=35A059704
- Integers n > 1997 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 1997.at n=6A063055
- Primes of the form 2^i*3^j - (i+j) with i, j >= 0.at n=14A069356
- a(n) = 2^(2*n+1)*Sum_{k=1..2*n} binomial(2*n+1,k)*Bernoulli(k)/2^k.at n=5A069993