841
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 3
- Divisor Sum
- 871
- Proper Divisor Sum (Aliquot Sum)
- 30
- 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
- 812
- Möbius Function
- 0
- Radical
- 29
- Omega Function (Ω)
- 2
- 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
- yes
- 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
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- no
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- yes
- Achilles Number
- no
- Perfect Power
- yes
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Names
- German
- achthunderteinundvierzig· ordinal: achthunderteinundvierzigste
- English
- eight hundred forty-one· ordinal: eight hundred forty-first
- Spanish
- ochocientos cuarenta y uno· ordinal: 841º
- French
- huit cent quarante et un· ordinal: huit cent quarante et unième
- Italian
- ottocentoquarantuno· ordinal: 841º
- Latin
- octingenti quadraginta unus· ordinal: 841.
- Portuguese
- oitocentos e quarenta e um· ordinal: 841º
Appears in sequences
- n followed by n^2.at n=57A000463
- One half of the number of permutations of [n] such that the differences have 5 runs with the same signs.at n=1A000506
- a(n) = E(n+1) - 2*E(n), where E(i) is the Euler number A000111(i).at n=7A000708
- a(n) = ceiling(n^2/2).at n=41A000982
- Numbers n such that the sum of the squares of n consecutive positive odd numbers x^2 + (x+2)^2 + ... + (x+2n-2)^2 = k^2 for some integer k. The least values of x and k for each n are in A056131 and A056132, respectively.at n=51A001033
- Squares of primes.at n=9A001248
- Squares of Lucas numbers.at n=7A001254
- Associated Mersenne numbers.at n=14A001350
- Number of permutations of length n with longest increasing subsequence of length 6.at n=2A001457
- Perfect powers: m^k where m > 0 and k >= 2.at n=37A001597
- A Fielder sequence: a(n) = a(n-1) + a(n-3) + a(n-4), n >= 4.at n=14A001638
- Powerful numbers, definition (1): if a prime p divides n then p^2 must also divide n (also called squareful, square full, square-full or 2-powerful numbers).at n=47A001694
- Number of labeled graded partially ordered sets with n elements of height at most 1.at n=5A001831
- Centered square numbers: a(n) = 2*n*(n+1)+1. Sums of two consecutive squares. Also, consider all Pythagorean triples (X, Y, Z=Y+1) ordered by increasing Z; then sequence gives Z values.at n=20A001844
- Squares and cubes.at n=35A002760
- Solid partitions of n which are restricted to two planes.at n=9A002835
- Expansion of (1 + x - x^5) / (1 - x)^3.at n=36A004120
- Alternate Lucas numbers - 2.at n=7A004146
- Divisible only by primes congruent to 4 mod 5.at n=38A004618
- Numbers divisible only by primes congruent to 1 mod 7.at n=25A004619