9876
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 30
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 23072
- Proper Divisor Sum (Aliquot Sum)
- 13196
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3288
- Möbius Function
- 0
- Radical
- 4938
- Omega Function (Ω)
- 4
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 135
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- Number of unrooted triangulations of a disk with 2 internal nodes and n+3 nodes on the boundary.at n=7A005504
- n written in fractional base 10/9.at n=36A024664
- 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=26A031564
- Numbers k such that 117*2^k+1 is prime.at n=20A032408
- Numbers k such that 241*2^k+1 is prime.at n=5A032497
- Floor[(80/81)*10^n].at n=3A057933
- a(n) = (10^n - 1)*(80/81) + n/9.at n=3A064617
- Reverse concatenation of next n numbers with a(1) = 0.at n=3A080483
- 2*3*5*6*...*a(n) -+ 1 are primes, with a(n+1) > a(n).at n=36A087900
- Row sums of triangle in A090285.at n=7A090317
- Fourth diagonal (m=3) of triangle A084938; a(n) = A084938(n+3,n) = (n^3 + 9*n^2 + 26*n)/6.at n=36A092286
- Smallest available integer which fits into the repeating pattern 9876543210.at n=19A098756
- Nonnegative numbers with digits in descending order that differ exactly by 1.at n=33A138142
- Ulam's spiral (ENE spoke).at n=25A143856
- a(n) = largest n-distinct-decimal-digit number such that the string formed by the last k digits is divisible by k for any 1<=k<=n.at n=3A147637
- Coefficient triangle sequence of a polynomial recursion: p(x,n)=(x + 1)*(p(x, n - 1) + 3^(n - 2)*(x + x^Floor[n/2] + x^(n - 2))); Row sums are 2*3^n.at n=56A153311
- Start with 0; then add one to each single digit.at n=36A158699
- Array T(n,k) read by antidiagonals: T(n,k) is the number of [n,k]-triangulations in the plane, n >= 0, k >= 0.at n=47A169808
- a(1) = 10; a(n) = a(n-1)*10 - 2^(n-2).at n=3A179556
- Largest multiple of n which is a concatenation of the n numbers n(n-1)/2,...,n(n+1)/2-1, or 0 if no such number exists.at n=3A193381