9874
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 14814
- Proper Divisor Sum (Aliquot Sum)
- 4940
- 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
- 4936
- Möbius Function
- 1
- Radical
- 9874
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 135
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- n written in fractional base 10/9.at n=34A024664
- Number of partitions of n that do not contain 8 as a part.at n=34A027342
- 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 98.at n=17A031596
- Numbers whose set of base-8 digits is {2,3}.at n=38A032808
- Values of A038007 not ending in 6 or 8.at n=15A038009
- Numbers having four 2's in base 8.at n=25A043432
- Numbers whose base-5 representation contains exactly two 3's and three 4's.at n=30A045303
- 5 x n binary matrices with 1 unit column up to row and column permutations.at n=5A057970
- a(n) = sum of modular offsets: mod[n+c,b]-(mod[n,b]+c) for c<=b<=n.at n=44A066809
- a(n) = A051201(n^2).at n=44A078163
- Number of unlabeled and connected graphs on n vertices which are semi-P4-sparse (G is semi-P4-sparse iff G has no induced P5, House, or complement of a fork).at n=9A079469
- Triangle T, read by rows, where column k of T = column 0 of T^(k+1) for k>0, with column 0 of T = column 0 of T^4 shift right.at n=22A138271
- Column 1 of triangle A138271; also, column 0 of matrix power A138271^2.at n=5A138273
- Number of (n+1) X 8 0..2 arrays with every 2 X 2 subblock having nonzero determinant and commuting with every horizontal or vertical neighbor.at n=10A207148
- Proceed counterclockwise on the outer keys of a numeric keypad (i.e., 1,2,3,6,9,8,7,4): first single digits, then concatenate two digits, then three, etc.at n=28A249182
- Numbers n such that the decimal expansions of both n and n^2 have 4 as the digit with the smallest value and 9 as the digit with the largest value.at n=2A254072
- The crystallogen sequence (a(n) = A018227(n)-4).at n=35A271996
- Numbers k such that k^2+1, (k+2)^2+1 and (k+6)^2+1 are prime.at n=19A302021
- a(1) = 2; for n > 1, a(n) is the least positive number not yet in the sequence such that Sum_{k=1..n} a(k) divides Sum_{k=1..n} a(k)^2.at n=42A318358
- Numbers that have decimal expansion c(1)c(2)...c(n) with distinct digits that satisfy c(1) <> 0, c(1) is the largest digit, and for each i in 1..n there is j in {0, 1} such that c(i) == 2*c(i-1) + j (mod 10) (with c(0): = c(n)).at n=8A336670