12980
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 30240
- Proper Divisor Sum (Aliquot Sum)
- 17260
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4640
- Möbius Function
- 0
- Radical
- 6490
- Omega Function (Ω)
- 5
- 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
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 138
- 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 ways to place a non-attacking white and black bishop on n X n chessboard.at n=10A035288
- Add the next prime and multiply by the next prime.at n=5A087297
- Number of binary words of length n containing at least one subword 1000001 and no subwords 10^{i}1 with i<5.at n=38A143285
- a(n) = 1000*n - 20.at n=12A157515
- G.f.: Product_{n>=1} (1 + x^n + x^(n+1)).at n=36A160571
- Numbers n with property that (n+1)*prime(n+1)-n*prime(n) is a perfect square s^2.at n=28A181283
- Number of 5-step S, E, and NW-moving king's tours on an n X n board summed over all starting positions.at n=17A187510
- Number of transpose partition pairs of order n whose number of odd parts differ by numbers of the form 4*k + 2.at n=44A190101
- Number of n X 2 arrays of the minimum value of corresponding elements and their horizontal or diagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 n X 2 array.at n=19A220147
- Number of partitions of n that have even-sized Ferrers matrix.at n=37A238945
- Number of 2-separable partitions of n; see Comments.at n=50A239468
- Number of partitions of n such that m(2) = m(3), where m = multiplicity.at n=43A240064
- Expansion of 1/(1 - Sum_{k>=0} x^((2*k+1)^2)).at n=53A280863
- Number of 4-element subsets of [n] having a prime element sum.at n=32A320679
- a(n) = Sum_{k=1..n} (k/gcd(n, k))^2.at n=38A332654
- After initial 0, numbers k such that A327860(k) is a multiple of k.at n=44A351087
- Numbers k such that the odd part of sigma(sigma(k)) is equal to the odd part of sigma(k).at n=32A353365