1923
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 2568
- Proper Divisor Sum (Aliquot Sum)
- 645
- 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
- 1280
- Möbius Function
- 1
- Radical
- 1923
- 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
- 50
- 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
- Juxtapose pairs of primes (starting at 1).at n=4A007794
- Poincaré series [or Poincare series] of Lie algebra associated with a certain braid group.at n=8A007993
- Coordination sequence T2 for Zeolite Code MTT.at n=27A008190
- Super-3 Numbers (3n^3 contains substring '333' in its decimal expansion).at n=12A014569
- Numbers k such that Fibonacci(k) == 2 (mod k).at n=34A023174
- a(n) = position of n^2 + (n+1)^2 + (n+2)^2 in A000408.at n=26A024802
- 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=35A024820
- 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=33A024833
- a(n) = least m such that if r and s in {1/1, 1/3, 1/5, ..., 1/(2n-1)} satisfy r < s, then r < k/m < (k+3)/m < s for some integer k.at n=16A024844
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 43.at n=6A031541
- Lucky numbers with size of gaps equal to 10 (lower terms).at n=21A031892
- Numbers k such that 135*2^k+1 is prime.at n=36A032417
- Concatenation of n and n + 4 or {n,n+4}.at n=18A032609
- Lucky numbers that are concatenations of n with n + 4.at n=3A032654
- Decimal part of a(n)^(1/10) starts with n (10th powers excluded).at n=13A034065
- a(0)=2; a(n) is the smallest k > a(n-1) such that the fractional part of k^(1/10) starts with n.at n=13A034075
- a(n) = 2*A040027(n-1) + Bell(n), where Bell = A000110.at n=7A038559
- Number of partitions satisfying cn(2,5) < cn(1,5) + cn(4,5) and cn(3,5) < cn(1,5) + cn(4,5).at n=26A039889
- Numerators of continued fraction convergents to sqrt(962).at n=1A042860
- Denominators of continued fraction convergents to sqrt(963).at n=2A042863