8981
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 10272
- Proper Divisor Sum (Aliquot Sum)
- 1291
- 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
- 7692
- Möbius Function
- 1
- Radical
- 8981
- 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
- 47
- 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
- no
- Odd
- yes
Appears in sequences
- Numbers k such that 45*2^k - 1 is prime.at n=49A002242
- Numerators of continued fraction convergents to sqrt(411).at n=7A041780
- a(1) = 6; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=45A046256
- T(n,n+1), array T given by A047000.at n=8A047006
- a(1) = 9; a(n) is smallest number > a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=47A074345
- Expansion of (1-x)^(-1)/(1-2*x^2-2*x^3).at n=16A077879
- Number of partitions of n^2 into squares greater than 1.at n=18A092362
- a(n)=(a^n-b^n)/(a-b), where a=1.3802775690976141157... and b=-0.8191725133961644397... are the real roots of x^4-x^3-1=0.at n=29A097719
- A triangular array related to A077028 and distributing the values of A007582.at n=41A110552
- Triangle read by rows: T(n,k) is the number of directed column-convex polyominoes of area n and having k cells in the longest column (1<=k<=n).at n=69A121300
- G.f.: Sum_{n>=0} x^n * (1+x)^(2^n).at n=8A121688
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 1, -1), (0, 1, -1), (1, -1, -1), (1, 1, 1)}.at n=8A149513
- Number of partitions p = [x(1), ..., x(k)], where x(1) >= x(2) >= ... >= x(k), of n such that max(x(i) - x(i-1)) >= number of parts of p.at n=41A241831
- Number of nonnegative integers with property that their base 7/6 expansion (see A024643) has n digits.at n=50A245402
- If, for some m, A098550(m-2) is a prime p and A098550(m) = 7p, add 7p to the sequence.at n=41A253054
- Numbers n such that n!! - 2^8 is prime.at n=23A265114
- Number of partitions of n for which the number of even parts is equal to the positive alternating sum of the parts.at n=47A277579
- Number of nX6 0..1 arrays with every element equal to 0, 1, 3 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=6A302633
- Number of 7Xn 0..1 arrays with every element equal to 0, 1, 3 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=5A302640
- Number of ways to write n as an ordered sum of 10 nonzero triangular numbers.at n=20A340955