9931
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 9932
- 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
- 9930
- Möbius Function
- -1
- Radical
- 9931
- 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
- 117
- 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
- 1225
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Quintan primes: p = (x^5 + y^5)/(x + y).at n=14A002650
- a(n) = prime(n^2).at n=34A011757
- 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=12A031597
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 70 ones.at n=8A031838
- Number of partitions of n into parts 3k+1 and 3k+2 with at least one part of each type.at n=43A035620
- Number of partitions satisfying cn(0,5) + cn(2,5) <= cn(1,5) and cn(0,5) + cn(2,5) <= cn(4,5) and cn(0,5) + cn(3,5) <= cn(1,5) and cn(0,5) + cn(3,5) <= cn(4,5).at n=44A039883
- Discriminants of imaginary quadratic fields with class number 23 (negated).at n=24A046020
- Primes of the form 30*p + 1 where p is also prime.at n=27A051646
- Prime number spiral (clockwise, Northwest spoke).at n=17A053999
- Numbers k such that 3*5^k - 2 is prime.at n=22A057917
- a(n) = least odd number which can be represented in the form p + 2*k^2, k>0, in n different ways.at n=43A060004
- Prime numbers with odd digits in descending order.at n=31A061245
- Primes with 10 as smallest positive primitive root.at n=26A061323
- Primes p for which the exponent of the highest power of 2 dividing p! is equal to prevprime(prevprime(p)).at n=38A064396
- Cycle of the inventory sequence (as in A063850) starting with n consists of prime numbers.at n=32A078970
- Let n range through the odd numbers skipping multiples of 5; a(n) = n-th prime ending in n.at n=12A089779
- a(n) = (n+1)*prime(n) + n*prime(n+1).at n=33A097240
- Primes of the form (k+1)*prime(k) + k*prime(k+1).at n=14A097241
- Reverse digits of largest primes, append to sequence if result is larger prime then previous one with reverse digits.at n=17A098922
- Numbers k such that 9*10^k + R_k + 6 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=12A100473