9923
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
- 9924
- 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
- 9922
- Möbius Function
- -1
- Radical
- 9923
- 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
- 73
- 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
- 1223
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers k such that the continued fraction for sqrt(k) has period 70.at n=39A020409
- a(n) = least m such that if r and s in {1/1, 1/4, 1/7, ..., 1/(3n-2)} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.at n=44A024836
- 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=11A031597
- Upper prime of a difference of 16 between consecutive primes.at n=32A031935
- Number of partitions of n with equal nonzero number of parts congruent to each of 1, 2 and 3 (mod 4).at n=56A046781
- Triangle T(n,k) is the number of restricted growth strings (RGS) of set partitions of {1..n} that have an increase at index k (1<=k<n).at n=32A056861
- Discriminants of imaginary quadratic fields with class number 25 (negated).at n=16A056987
- Primes p such that x^41 = 2 has no solution mod p.at n=30A059236
- Treated as strings, n begins with Floor(sqrt(n)).at n=46A069086
- Primes which are sandwiched between two numbers having the same unordered canonical form.at n=29A074460
- Sum of odd-indexed primes.at n=45A077131
- a(n) = smallest prime > n*prime(n).at n=46A079779
- Primes whose 10's complement is a palindrome.at n=48A083017
- Smallest prime x > n such that x (mod n) = x (mod prime(n)).at n=46A091313
- Prime partial sums of the odd-indexed primes.at n=6A096208
- Primes from merging of 4 successive digits in decimal expansion of the Euler-Mascheroni constant A001620.at n=3A104938
- Primes such that the sum of the predecessor and successor primes is divisible by 29.at n=37A112859
- Number of partitions of 1 into distinct fractions i/j with 1<=i<j<=n and i,j coprime.at n=23A116084
- Start with 1 and repeatedly reverse the digits and add 67 to get the next term.at n=37A118214
- Records in A018892.at n=49A126097