845
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 1098
- Proper Divisor Sum (Aliquot Sum)
- 253
- 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
- 624
- Möbius Function
- 0
- Radical
- 65
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 41
- 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
- achthundertfünfundvierzig· ordinal: achthundertfünfundvierzigste
- English
- eight hundred forty-five· ordinal: eight hundred forty-fifth
- Spanish
- ochocientos cuarenta y cinco· ordinal: 845º
- French
- huit cent quarante-cinq· ordinal: huit cent quarante-cinqième
- Italian
- ottocentoquarantacinque· ordinal: 845º
- Latin
- octingenti quadraginta quinque· ordinal: 845.
- Portuguese
- oitocentos e quarenta e cinco· ordinal: 845º
Appears in sequences
- a(n) = a(n-1) + a(n-2) - 2, a(0) = 4, a(1) = 3.at n=14A000211
- Numbers m such that Fibonacci(m) ends with m.at n=29A000350
- Numbers that are the sum of 2 squares in exactly 3 ways.at n=5A000443
- Increasing blocks of digits of e.at n=5A001114
- Number of solutions to a linear inequality.at n=26A002797
- a(n) = 1000*log_10(n) rounded down.at n=6A004225
- a(n) = 1000*log_10(n) rounded to the nearest integer.at n=6A004226
- a(n) = floor(n*phi^8), where phi is the golden ratio, A001622.at n=18A004923
- Sum of squares of primes dividing n.at n=57A005063
- Sum of squares of primes = 2 mod 3 dividing n.at n=57A005075
- Sequence and first differences (A030124) together list all positive numbers exactly once.at n=36A005228
- P-positions in Epstein's Put or Take a Square game.at n=25A005240
- 1 + (sum of first n odd primes - n)/2.at n=30A005521
- Coordination sequence T4 for Zeolite Code AFO.at n=19A008018
- Coordination sequence T2 for Zeolite Code PHI.at n=21A008228
- Smallest number strictly greater than previous one which is the sum of squares of two previous distinct terms (a(1)=1, a(2)=2).at n=9A008318
- a(n+1) = a(n)-b(n+1) if a(n) >= b(n+1) else a(n)+b(n+1), where {b(n)} are the triangular numbers A000217.at n=33A008345
- Molien series for 6-dimensional complex reflection group 4.U_4 (3) of order 2^9 .3^7 .5.7.at n=28A008581
- Numbers k such that the continued fraction for sqrt(k) has period 5.at n=23A010337
- Expansion of Product_{k>=1} (1 - x^k)^13.at n=9A010820