7850
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 14694
- Proper Divisor Sum (Aliquot Sum)
- 6844
- 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
- 3120
- Möbius Function
- 0
- Radical
- 1570
- Omega Function (Ω)
- 4
- 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
- 26
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- yes
- Odd
- no
Appears in sequences
- Expansion of 1/((1-x)(1-8x)(1-9x)(1-10x)).at n=3A024771
- a(n) = (d(n)-r(n))/2, where d = A026057 and r is the periodic sequence with fundamental period (0,0,1,0).at n=38A026058
- Numbers k such that 69*2^k+1 is prime.at n=19A032384
- Numerators of continued fraction convergents to sqrt(629).at n=4A042206
- Base-7 palindromes that start with 3.at n=29A043017
- Smallest number m such that m^2+1 is divisible by A002144(n)^2 (= squares of primes congruent to 1 mod 4).at n=29A059321
- List of codewords in binary lexicode with Hamming distance 5 written as decimal numbers.at n=30A075931
- a(n) = (n-4)^(n-3) - (n-3)^(n-4) + 1.at n=5A111454
- Expansion of q / (chi(-q) * chi(-q^3) * chi(-q^5) * chi(-q^15)) in powers of q where chi() is a Ramanujan theta function.at n=38A123632
- Triangle read by rows: T(n,k) is the number of deco polyominoes of height n in which the maximal number of initial consecutive columns ending at the same level is k (1 <= k <= n).at n=59A140709
- a(n) = n^(n+1)-(n+1)^n+1-(-1)^prime(n+1)-(-1)^(n+1).at n=5A141074
- a(n) = 25*n^2 - 14*n + 2.at n=18A154357
- a(n) = 2^(prime(n)-1) mod prime(n)^2.at n=38A196202
- Numbers which are the sum of two squared primes in exactly two ways (ignoring order).at n=41A226539
- a(n) = n*(n^2 + 3)/2.at n=25A229183
- Number of paths from (0,0) to (n,3), with vertices (i,k) satisfying 0 <= k <= 3, consisting of segments given by the vectors (1,1), (1,2), (1,-1).at n=15A247326
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 206", based on the 5-celled von Neumann neighborhood.at n=29A270735
- Number of 3 X n 0..1 arrays with no element equal to more than two of its horizontal, diagonal or antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.at n=8A281402
- a(1) = 1; a(n) = Sum_{k=1..n} a(ceiling((n-1)/k)).at n=32A290845
- Number of even permutations s of {1,2,...,n} such that |s(i)-i| > 1 for each i=1,2,...,n.at n=9A293044