9880
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 32
- Divisor Sum
- 25200
- Proper Divisor Sum (Aliquot Sum)
- 15320
- 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
- 3456
- Möbius Function
- 0
- Radical
- 2470
- Omega Function (Ω)
- 6
- Little Omega Function (ω)
- 4
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
- yes
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 135
- Smith Number
- yes
- 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
- Tetrahedral (or triangular pyramidal) numbers: a(n) = C(n+2,3) = n*(n+1)*(n+2)/6.at n=38A000292
- Number of compositions of n into 4 ordered relatively prime parts.at n=37A000742
- Number of board-pair-pile polyominoes with n cells.at n=8A001170
- Sum of the first n even squares: a(n) = 2*n*(n+1)*(2*n+1)/3.at n=19A002492
- Binomial coefficient C(4n,n-7).at n=3A004337
- Binomial coefficient C(5n,n-5).at n=3A004347
- Binomial coefficient C(8n,n-2).at n=3A004383
- Binomial coefficient C(40,n).at n=3A010956
- Binomial coefficient C(n,37).at n=3A010990
- Number of segments (and sides) created by diagonals of an n-gon in general position.at n=17A014628
- Even tetrahedral numbers.at n=28A015220
- a(n) = A027082(n, 2n-5).at n=8A027092
- a(n) = (prime(n)-3)*(prime(n)-5)*(prime(n)-7)/48.at n=21A030003
- Least Smith number having digital sum A033662(n).at n=12A033663
- Number of colors that can be mixed with up to n units of yellow, blue, red.at n=40A048134
- a(n) = Sum_{i=0..2n} (-1)^i * T(i,2n-i), array T as in A049723.at n=39A049725
- T(n,3), array T as in A050186; a count of aperiodic binary words.at n=37A050188
- 16-gonal (or hexadecagonal) numbers: a(n) = n*(7*n-6).at n=38A051868
- Numbers k such that k*Sum_{d|k} 1/sigma(d) is an integer.at n=17A069166
- Take pairs (a, b), sorted on a, such that T(a)+T(b)=concatenation of a and b, where T(k) is the k-th triangular number A000217(k). Sequence gives values of b.at n=18A096032