4019
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
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 4020
- 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
- 4018
- Möbius Function
- -1
- Radical
- 4019
- 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
- 25
- 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
- yes
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 555
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Landau's approximation to population of x^2 + y^2 <= 2^n.at n=14A000690
- Primes of form 3*k^2 - 3*k + 23.at n=32A007637
- Coordination sequence T3 for Zeolite Code LTN.at n=44A008142
- Numbers k such that the continued fraction for sqrt(k) has period 50.at n=17A020389
- In base 11, a(n) = sum of digits of Lucas(a(n)).at n=34A025491
- 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 63.at n=3A031561
- Multiplicity of highest weight (or singular) vectors associated with character chi_30 of Monster module.at n=34A034418
- Trajectory of 40 under prime factor concatenation procedure.at n=25A037937
- Numerators of continued fraction convergents to sqrt(209).at n=5A041388
- Numerators of continued fraction convergents to sqrt(836).at n=7A042614
- Numbers having three 5's in base 9.at n=9A043475
- Primes p such that p+2 and 2p+1 are also prime.at n=34A045536
- Primes with first digit 4.at n=24A045710
- Discriminants of imaginary quadratic fields with class number 19 (negated).at n=13A046016
- Last member of a sexy prime quadruple: value of p+18 such that p, p+6, p+12 and p+18 are all prime.at n=16A046124
- p, p+2 and p+8 are primes.at n=34A046134
- Positions of 4-digit terms in the continued fraction for Pi (3 is at position 0).at n=3A048959
- Primes p such that p+2 and p+8 are also primes but p+6 is not.at n=24A049437
- Primes remaining prime if any digit is deleted (zeros allowed).at n=23A051362
- Positions in decimal expansion of Pi where next prime begins.at n=31A053013