7419
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9896
- Proper Divisor Sum (Aliquot Sum)
- 2477
- 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
- 4944
- Möbius Function
- 1
- Radical
- 7419
- 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
- 70
- 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
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (F(2), F(3), ...), t = A000201 (lower Wythoff sequence).at n=20A024593
- n written in fractional base 10/7.at n=39A024662
- 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 56.at n=36A031554
- Lucky numbers with size of gaps equal to 14 (upper terms).at n=38A031897
- Lucky numbers with size of gaps equal to 16 (lower terms).at n=22A031898
- Pseudo-random numbers: a (very weak) pseudo-random number generator from the second edition of the C book.at n=7A061364
- Integers n > 7059 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 7059.at n=3A063058
- C(n+3)=2*C(n), where C(n) is Cototient(n) := n - phi(n) (A051953).at n=41A063480
- Sum of the remainders when the n-th triangular number is divided by all smaller triangular numbers > 1.at n=48A072524
- a(n) = round(10000*log(n/10)).at n=20A104077
- Generalized Mancala solitaire (A002491); to get n-th term, start with n and successively round up to next 8 multiples of n-1, n-2, ..., 1, for n>=1.at n=44A113745
- Numbers k such that 6*k + 7 = p^2 (p=prime).at n=44A171140
- Positive integers of the form (2*m^2+1)/11.at n=36A179088
- Numbers n with property that (n+1)*prime(n+1)-n*prime(n) is a perfect square s^2.at n=23A181283
- Numbers n such that in Collatz (3x+1) trajectory of n, the number of terms < n equals number of terms > n.at n=20A217731
- Sequence of semiprimes with all cumulating sums being semiprime.at n=11A254325
- a(n) is the largest k such that the sum of k consecutive reciprocals 1/p_n + ... + 1/p_(n+k-1) does not exceed 1 (where p_n = n-th prime).at n=16A327600
- Number of grid-filling curves of order n (on the square grid) with turns by +-90 degrees generated by folding morphisms that are self-avoiding but not plane-filling.at n=18A343990
- Numbers k >= 3 such that 1/d(k - 2) + 1/d(k - 1) + 1/d(k) is an integer, d(i) = A000005(i).at n=43A359056
- Number of partitions of n whose greatest part is a multiple of 5.at n=40A363047