9942
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 19896
- Proper Divisor Sum (Aliquot Sum)
- 9954
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 3312
- Möbius Function
- -1
- Radical
- 9942
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- yes
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Minimal number of people to give a 50% probability of having at least n coincident birthdays in one year.at n=43A014088
- 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 66.at n=30A031564
- Numbers k such that x = 2^k-2 satisfies phi(x)+2 = phi(x+2).at n=21A050475
- Least k such that k*(Mersenne_prime(n)^2) + 1 is prime.at n=18A098819
- Let M be the matrix defined in A111490. Sequence gives M(2,1)-M(1,2), M(2,1)+M(3,1)+M(3,2)-M(1,2)-M(1,3)-M(2,3), etc.at n=44A123329
- E.g.f. satisfies: A(x) = x*(exp(sinh(A(x)))).at n=6A134200
- 6 times centered hexagonal numbers: 18*n*(n+1) + 6.at n=23A164016
- Number of nondecreasing arrangements of 4 nonzero numbers in -(n+2)..(n+2) with sum zero.at n=32A188334
- Number of (n+2) X 4 binary arrays avoiding patterns 001 and 110 in rows, columns and nw-to-se diagonals.at n=15A202441
- Triangle of coefficients of polynomials u(n,x) jointly generated with A209418; see the Formula section.at n=61A209417
- Number of (w,x,y) with all terms in {0,...,n} and |w-x|+|x-y|+|y-w| <= w+x+y.at n=23A213487
- Number of binary words w of length n with equal numbers of 010 and 101 subwords such that for every prefix of w the number of occurrences of subword 101 is larger than or equal to the number of occurrences of subword 010.at n=16A260697
- Growth series for affine Coxeter group (or affine Weyl group) D_9.at n=7A266764
- Growth series for affine Coxeter group B_9.at n=7A267172
- Expansion of Product_{k>=1} 1/((1 - x^prime(k))*(1 - x^(prime(k)^2))*(1 - x^(prime(k)^3))).at n=54A280715
- Numbers k such that (5*10^k - 101)/3 is prime.at n=18A282506
- Numbers k such that f(k), f(k+1) and f(k+2) are all primes, where f(k) = (2k+1)^2 - 2 (A073577).at n=34A293620
- Irregular table read by rows: Take a Reuleaux triangle with all diagonals drawn, as in A340639. Then T(n,k) = number of k-sided polygons in that figure for k >= 3.at n=42A340614
- a(n) is the smallest k such that k!'s prime(n)-smooth part is less than its prime(n+1)-rough part.at n=24A360316
- Number of integer partitions of n with all distinct lengths of maximal gapless runs (decreasing by 0 or 1).at n=36A384884