1949
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 1950
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 1948
- Möbius Function
- -1
- Radical
- 1949
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 143
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 296
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers k such that (k^2 + k + 1)/19 is prime.at n=43A002643
- a(n) = 3*n^2 + 3*n - 1.at n=25A004538
- Primes with both 10 and -10 as primitive root.at n=56A007349
- Smallest prime > n^2.at n=43A007491
- Prime(n)*...*a(n) is the least product of consecutive primes which is non-deficient.at n=12A007686
- Prime(n)*...*a(n) is the least product of consecutive primes which is abundant.at n=12A007708
- Coordination sequence T3 for Zeolite Code BRE.at n=29A008060
- Coordination sequence T1 for Scapolite.at n=28A008262
- Expansion of 1/( Product_{j=0..5} (1-x^(2*j+1)) ).at n=58A008675
- Least m such that if a/b < c/d are Farey fractions of order n then there exists k such that a/b < k/m < c/d, k/m reduced.at n=49A009571
- Numbers k such that the continued fraction for sqrt(k) has period 9.at n=19A010339
- a(n) is prime and sum of all primes <= a(n) is prime.at n=29A013917
- Number of squares on infinite chessboard at <= n knight's moves from a fixed square.at n=12A018836
- n-th composite is sum of first k composites for some k.at n=42A020642
- a(n)-th nonsquarefree is sum of first k nonsquarefrees for some k.at n=27A020644
- Conjectured number of irreducible multiple zeta values of depth 8 and weight 2n+22.at n=10A022496
- Primes that remain prime through 2 iterations of the function f(x) = 2x + 9.at n=40A023245
- Primes that remain prime through 2 iterations of function f(x) = 7x + 6.at n=26A023259
- a(n) = T(n,n+4), T given by A027023.at n=6A027026
- a(n) = T(n,2n-6), T given by A027023.at n=7A027030