8987
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 32
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 10560
- Proper Divisor Sum (Aliquot Sum)
- 1573
- 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
- 7560
- Möbius Function
- -1
- Radical
- 8987
- 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
- 91
- Smith Number
- no
- 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
- no
- Odd
- yes
Appears in sequences
- Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite CHI = Chiavennite Ca4Mn4[Be8Si20O52(OH)8].8H2O starting with a T4 atom.at n=14A019094
- Sort then Add, a(1)=5.at n=12A033894
- Sort then Add, a(1)=31.at n=9A033905
- Sort then Add, a(1)=20.at n=10A033906
- Sum of digits = 8 times number of digits.at n=32A061425
- Numbers n for which there are exactly seven k such that n = k + reverse(k).at n=25A072431
- Right-angled numbers with an internal digit as the vertex.at n=46A135602
- Numbers k such that |2^(2*k-27)-27| is prime.at n=9A138598
- a(n) = 25*n^2 - 2*n.at n=18A154376
- Number of nX2 0..2 arrays with values 0..2 introduced in row major order, the number of instances of each value within one of each other, and every element equal to one or two horizontal or vertical neighbors.at n=8A199035
- T(n,k)=Number of nXk 0..2 arrays with values 0..2 introduced in row major order, the number of instances of each value within one of each other, and every element equal to one or two horizontal or vertical neighbors.at n=46A199041
- Number of length 5 nonnegative integer arrays starting and ending with 0 with adjacent elements unequal but differing by no more than n.at n=18A205342
- Number of compositions of n where the difference between largest and smallest parts equals 10 and adjacent parts are unequal.at n=14A214279
- Number of ABC triples with quality q > 1 and c < 10^n.at n=7A216370
- Numbers k such that 25*k+1 is a square.at n=37A219259
- Number of "abc-hits" with c < 10^n.at n=7A225425
- Number of partitions of n, where the difference between the number of odd parts and the number of even parts is 6.at n=43A240015
- Numbers k dividing every cyclic permutation of k^k.at n=43A262814
- a(n) = n*(n + 5)*(n + 10)/6.at n=33A264443
- G.f.: Product_{i>=1, j>=1} (1 + x^(i*j))^(i*j).at n=12A280541