12880
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 40
- Divisor Sum
- 35712
- Proper Divisor Sum (Aliquot Sum)
- 22832
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4224
- Möbius Function
- 0
- Radical
- 1610
- Omega Function (Ω)
- 7
- 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
- yes
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 24
- 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
- Triangle of numbers arising from analysis of Levine's sequence A011784.at n=29A014621
- a(n) = 2*n*(4*n + 1).at n=40A033585
- a(n) = (n^2-1)*(2*n^2-1).at n=9A033595
- Number of nonempty subsets of {1,2,...,n} in which exactly 2/3 of the elements are <= sqrt(n).at n=37A048095
- A convolution triangle of numbers obtained from A034255.at n=17A048882
- a(n) is the number of n-tosses having a run of 5 or more heads for a fair coin (i.e., probability is a(n)/2^n).at n=15A050233
- Triangular numbers of the form 10*k.at n=32A069498
- Triangular number x such that x + reverse of x is a prime.at n=5A072387
- Products of members of pairs in A075333.at n=27A075337
- Triangular numbers which are 7-almost primes.at n=7A076581
- Triangular numbers which are also happy numbers (cf. A007770).at n=22A076712
- Triangular number pertaining to A081974. a(n) = A081974(n)*A081974(n+1).at n=44A081975
- Sort the digits of these triangular numbers into descending order and drop zeros to get primes.at n=20A082923
- a(n) = (3*n+1)*(3*n+4).at n=37A085001
- Numbers n such that more than half of the reduced-residue system modulo 210 consists of primes in the following sense: in {210n + R} more than 24 = phi(210)/2 primes occur, i.e., 25-33, 35, 46.at n=56A095392
- Consider the family of multigraphs enriched by the species of partitions. Sequence gives the triangle read by rows giving coefficients of polynomials arising from enumeration of those multigraphs on n edges of 5 different colors.at n=17A098346
- Number of squares on infinite half chessboard at <=n knight moves from a fixed point on the diagonal.at n=43A098499
- Imaginary part of the Gaussian multiperfect number associated with the real part A100884.at n=35A100885
- a(1) = 932; for n > 1, a(n) = a(n-1) + 1 + sum of distinct prime factors of a(n-1) that are < a(n-1).at n=34A105213
- Number of 3 X 3 magic squares (with distinct positive entries) having all entries < n.at n=47A108576