5419
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 5420
- 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
- 5418
- Möbius Function
- -1
- Radical
- 5419
- 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
- 41
- 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
- 716
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Table T(n,k) in which n-th row lists prime factors of 2^n + 1 (n >= 0), with repetition.at n=47A001269
- Smallest primitive factor of 2^(2n+1) + 1.at n=10A002185
- Cuban primes: primes which are the difference of two consecutive cubes.at n=22A002407
- Largest prime factor of 2^n + 1.at n=21A002587
- Largest primitive factor of 2^(2n+1) + 1.at n=10A002589
- Hex (or centered hexagonal) numbers: 3*n*(n+1)+1 (crystal ball sequence for hexagonal lattice).at n=42A003215
- Divisors of 2^42 - 1.at n=25A003547
- Largest prime factor of 2^n - 1.at n=40A005420
- Coordination sequence T2 for Keatite.at n=41A009845
- Coordination sequence for FeS2-Pyrite, S position.at n=34A009956
- Cyclotomic polynomials at x=-2.at n=21A020501
- Let q_k = p*(p+2) be product of k-th pair of twin primes; sequence gives values of p+2 such that (q_k)^2 > q_{k-i}*q_{k+i} for all 1 <= i <= k-1.at n=36A021007
- a(n) = least m such that if r and s in {1/3, 1/6, 1/9,..., 1/3n} satisfy r < s, then r < k/m < s for some integer k.at n=47A024824
- a(n) = (d(n)-r(n))/5, where d = A026057 and r is the periodic sequence with fundamental period (1,0,3,1,0).at n=47A026059
- Euler transform of Thue-Morse sequence A001285.at n=20A029877
- 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 73.at n=9A031571
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 40 ones.at n=19A031808
- Number of partitions satisfying (cn(1,5) = cn(4,5) and cn(0,5) <= cn(2,5) and cn(0,5) <= cn(3,5) and cn(1,5) <= cn(2,5) and cn(1,5) <= cn(3,5)).at n=48A036817
- Gaps of 10 in sequence A038593 (upper terms).at n=4A038660
- Numbers ending with '9' that are the difference of two positive cubes.at n=22A038864