7847
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 9600
- Proper Divisor Sum (Aliquot Sum)
- 1753
- 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
- 6264
- Möbius Function
- -1
- Radical
- 7847
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- 127
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- Sum of 12 nonzero 8th powers.at n=18A003390
- 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=51A036817
- a(n) = 10*n^2 + 7.at n=28A061722
- n sets a new record for number of iterations to reach 1 in the juggler sequence problem.at n=15A094679
- After the first two terms, each subsequent term is the smallest integer that is an outlier of the previous dataset, based on the criterion of 3 sample standard deviations above the mean.at n=38A103231
- Odd interprimes divisible by 19.at n=18A126231
- Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, -1), (-1, 1), (0, -1), (1, -1), (1, 0), (1, 1)}.at n=8A151480
- Row sums of A154685.at n=18A151675
- a(n) = 36*n^2 - 17*n + 2.at n=14A157265
- Products of 3 distinct non-Sophie Germain primes.at n=26A157347
- Multiples of 19 whose digit reversal - 1 is also a multiple of 19.at n=19A166399
- Irregular triangle C(n,g) counting the connected 5-regular simple graphs on 2n vertices with girth exactly g.at n=4A184950
- Number of connected 5-regular (or quintic) simple graphs on 2n vertices with girth exactly 3.at n=6A184953
- Triangular array C(n,r) = number of connected r-regular graphs, having girth exactly 3, with n nodes, for 0 <= r < n.at n=71A186733
- Number of 5-step S, NW and NE-moving king's tours on an n X n board summed over all starting positions.at n=12A187379
- First occurrence of n in A213859.at n=63A213861
- a(n) = n*(11*n-5)/2.at n=38A226492
- Numbers k whose decimal expansion can be split into at least two parts whose binary equivalents can be concatenated (in the same order) to form the binary expansion of the original number k.at n=7A237041
- Integers of the form 8k+7 that can be written as a sum of four distinct 'almost consecutive' squares.at n=42A243577
- Integers of the form 8k + 7 that can be written as a sum of four distinct squares of the form m, m + 1, m + 3, m + 5, where m == 2 (mod 4).at n=10A243580