801
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 9
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 1170
- Proper Divisor Sum (Aliquot Sum)
- 369
- 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
- 528
- Möbius Function
- 0
- Radical
- 267
- Omega Function (Ω)
- 3
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 59
- Smith 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
- no
- Odd
- yes
Names
- German
- achthunderteins· ordinal: achthunderteinsste
- English
- eight hundred one· ordinal: eight hundred first
- Spanish
- ochocientos uno· ordinal: 801º
- French
- huit cent un· ordinal: huit cent unième
- Italian
- ottocentouno· ordinal: 801º
- Latin
- octingenti unus· ordinal: 801.
- Portuguese
- oitocentos e um· ordinal: 801º
Appears in sequences
- Number of partitions into non-integral powers.at n=11A000135
- Numbers beginning with letter 'e' in English.at n=14A000873
- Numbers k such that 19*2^k - 1 is prime.at n=17A001775
- Related to number of digraphs.at n=3A003084
- Numbers that are the sum of 10 positive 6th powers.at n=12A003366
- Numbers that are a sum of distinct positive cubes in more than one way.at n=17A003998
- Even numbers written backwards.at n=54A004093
- Pentagonal numbers written backwards.at n=27A004163
- a(n) = n*(5*n - 1)/2.at n=18A005476
- Horizontally symmetric numbers.at n=49A007284
- Add 7, then reverse digits.at n=45A007398
- Generated by a sieve: keep first number, drop every 2nd, keep first, drop every 3rd, keep first, drop every 4th, etc.at n=49A007952
- Number of nonsplit type 2 metacyclic 2-groups of order 2^n.at n=40A007981
- Coordination sequence T2 for Zeolite Code THO.at n=20A008239
- Crystal ball sequence for planar net 4.8.8.at n=24A008577
- Molien series for 4-dimensional complex reflection group of order 7680 (in powers of x^4).at n=47A008669
- a(n) = ceiling(n^2/3).at n=49A008810
- Expansion of (1+2*x^3+x^5)/((1-x)^2*(1-x^5)).at n=44A008823
- Numbers n such that n^2 and n have same last 2 digits.at n=33A008852
- a(1)=1, a(n) = n*16^(n-1) + a(n-1).at n=2A014931