9859
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 31
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 9860
- 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
- 9858
- Möbius Function
- -1
- Radical
- 9859
- 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
- 42
- 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
- 1217
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Number of partitions of 1/n into 4 reciprocals of positive integers.at n=18A020327
- a(n) = least m such that if r and s in {1/2, 1/4, 1/6, ..., 1/2n} satisfy r < s, then r < k/m < (k+4)/m < s for some integer k.at n=32A024848
- a(n) = T(2*n, n+2), T given by A027011.at n=5A027013
- a(n) = greatest number in row n of array T given by A027011.at n=14A027020
- Sums of six consecutive squares: a(n) = n^2 + (n+1)^2 + (n+2)^2 + (n+3)^2 + (n+4)^2 + (n+5)^2.at n=38A027865
- Primes of the form n^2 + (n+1)^2 + (n+2)^2 + (n+3)^2 + (n+4)^2 + (n+5)^2.at n=13A027867
- T(n, 2n-9), T given by A027960.at n=9A027971
- 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 99.at n=5A031597
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 64 ones.at n=12A031832
- Discriminants of imaginary quadratic fields with class number 21 (negated).at n=31A046018
- Primes of the form 4*k^2 + 4*k + 59.at n=40A048988
- Primes prime(k) for which A049076(k) = 3.at n=31A049079
- Primes p such that p, p+12, p+24 are consecutive primes.at n=5A052188
- Partial sums of A027964.at n=9A053298
- Primes p such that x^31 = 2 has no solution mod p.at n=35A059225
- Primes p such that x^53 = 2 has no solution mod p.at n=21A059258
- Primes starting and ending with 9.at n=26A062335
- Primes in the numerator of partial sums of A076476.at n=7A076477
- Primes whose 10's complement is a palindrome.at n=46A083017
- Prime(prime(n)) when prime(prime(n)) and n are twin primes.at n=14A087394