987
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 1536
- Proper Divisor Sum (Aliquot Sum)
- 549
- 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
- 552
- Möbius Function
- -1
- Radical
- 987
- 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
- yes
- 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
- 36
- Smith 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
Names
- German
- neunhundertsiebenundachtzig· ordinal: neunhundertsiebenundachtzigste
- English
- nine hundred eighty-seven· ordinal: nine hundred eighty-seventh
- Spanish
- novecientos ochenta y siete· ordinal: 987º
- French
- neuf cent quatre-vingt-sept· ordinal: neuf cent quatre-vingt-septième
- Italian
- novecentoottantasette· ordinal: 987º
- Latin
- nongenti octoginta septem· ordinal: 987.
- Portuguese
- novecentos e oitenta e sete· ordinal: 987º
Appears in sequences
- Number of partitions of n into prime parts.at n=52A000607
- Number of ways to represent n using the binary operator a * b = 2^a + b.at n=12A000630
- F(2n) = bisection of Fibonacci sequence: a(n) = 3*a(n-1) - a(n-2).at n=8A001906
- a(n) = 5*a(n-1) - a(n-2), with a(0) = 1 and a(1) = 2.at n=5A002310
- a(n) = a(n-1) + a(n-2) - a(n-3).at n=38A002798
- Numbers that are the sum of 7 positive 6th powers.at n=12A003363
- Fully multiplicative with a(prime(k)) = Fibonacci(k+2).at n=42A003965
- a(n) = C(n,1) + C(n,2) + C(n,3), or n*(n^2 + 5)/6.at n=18A004006
- a(n) = floor(n*phi^7), where phi is the golden ratio, A001622.at n=34A004922
- a(n) = round(n*phi^7), where phi is the golden ratio, A001622.at n=34A004942
- a(n) = round(n*phi^8), where phi is the golden ratio, A001622.at n=21A004943
- a(n) = ceiling(n*phi^8), where phi is the golden ratio, A001622.at n=21A004963
- a(n) = 3*a(n-2) - a(n-4), a(0)=0, a(1)=1, a(2)=1, a(3)=4. Alternates Fibonacci (A000045) and Lucas (A000032) sequences for even and odd n.at n=16A005013
- Related to representations as sums of Fibonacci numbers.at n=16A006133
- Denominators of expansion of sinh x / sin x.at n=23A006656
- Coordination sequence T1 for Zeolite Code PAU.at n=23A008219
- Multiples of 21.at n=47A008603
- a(n) = prime(n)*(prime(n-1)-1)/2.at n=12A014302
- Odd Fibonacci numbers.at n=10A014437
- Numbers k such that phi(k) | sigma_11(k).at n=42A015769