2813
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 2940
- Proper Divisor Sum (Aliquot Sum)
- 127
- 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
- 2688
- Möbius Function
- 1
- Radical
- 2813
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 172
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- Related to Gilbreath conjecture.at n=22A001549
- Centered square numbers: a(n) = 2*n*(n+1)+1. Sums of two consecutive squares. Also, consider all Pythagorean triples (X, Y, Z=Y+1) ordered by increasing Z; then sequence gives Z values.at n=37A001844
- Number of 4-colorings of cyclic group of order n.at n=10A007687
- Coordination sequence T1 for Zeolite Code GME and AFX.at n=40A008110
- Least d for which the number with continued fraction [n,n,n,n...] is in Q(sqrt(d)).at n=52A013946
- Pseudoprimes to base 75.at n=23A020203
- Strong pseudoprimes to base 75.at n=12A020301
- Number of partitions of n into 5 unordered relatively prime parts.at n=47A023025
- a(n) = least m such that if r and s in {1/2, 1/4, 1/6,..., 1/2n} satisfy r < s, then r < k/m < s for some integer k.at n=42A024820
- a(n) = least m such that if r and s in {1/1, 1/2, 1/3, ..., 1/n} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.at n=40A024833
- Least m such that if r and s in {1/4, 1/8, 1/12, ..., 1/4n} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.at n=20A024839
- a(n) = least m such that if r and s in {1/2, 1/4, 1/6, ..., 1/(2*n)} satisfy r < s, then r < k/m < (k+3)/m < s for some integer k.at n=19A024845
- a(n) = (d(n)-r(n))/2, where d = A026057 and r is the periodic sequence with fundamental period (0,0,1,0).at n=25A026058
- Sequence (a(n): n >= 1) that shifts left 2 places under the "CHK" (necklace, identity, unlabeled) transform and has initial terms a(1) = a(2) = 1.at n=14A032173
- Number of partitions of n into parts 3k or 3k+2.at n=46A035361
- Number of ternary rooted trees with n nodes and height at most 8.at n=12A036376
- Numerators of continued fraction convergents to sqrt(313).at n=5A041590
- Numbers k such that the string 6,5 occurs in the base 9 representation of k but not of k-1.at n=38A044310
- Numbers n such that string 1,3 occurs in the base 10 representation of n but not of n-1.at n=31A044345
- Numbers n such that string 6,5 occurs in the base 9 representation of n but not of n+1.at n=38A044691