1585
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 1908
- Proper Divisor Sum (Aliquot Sum)
- 323
- 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
- 1264
- Möbius Function
- 1
- Radical
- 1585
- Omega Function (Ω)
- 2
- 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
- 78
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- Numbers m such that Fibonacci(m) ends with m.at n=38A000350
- a(n) = round(1000*log_2(n)).at n=2A004266
- a(n) = ceiling(1000*log_2(n)).at n=2A004267
- Riordan numbers: a(n) = (n-1)*(2*a(n-1) + 3*a(n-2))/(n+1).at n=11A005043
- Centered triangular numbers: a(n) = 3*n*(n-1)/2 + 1.at n=32A005448
- Coordination sequence T1 for Zeolite Code DDR.at n=25A008071
- Coordination sequence T1 for Zeolite Code EAB.at n=29A008082
- Crystal ball sequence for planar net 3.6.3.6.at n=26A008580
- Expansion of (1 + 2*x^2 + x^3)/((1 - x)^2*(1 - x^3)).at n=48A008822
- a(n) = Sum_{k=1..n} k*phi(k).at n=18A011755
- Positive integers n such that 2^n == 2^5 (mod n).at n=51A015925
- Powers of fifth root of 10 rounded to nearest integer.at n=16A018142
- Powers of fifth root of 10 rounded up.at n=16A018143
- Irreducible quadruple Euler sums of weight 2n+10 (verified for n <= 14).at n=42A019449
- Numbers k such that the continued fraction for sqrt(k) has period 25.at n=6A020364
- Positive integers which apparently never result in a palindrome under repeated applications of the function A056964(x) = x + (x with digits reversed).at n=15A023108
- Numbers k such that Fibonacci(k) == -5 (mod k).at n=45A023165
- Convolution of A023532 and A001950.at n=38A023603
- a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k=floor((n+1)/2) and t = A002808 (composite numbers).at n=20A023863
- a(n) = position of n^3 + (n+1)^3 + (n+2)^3 in A024975.at n=16A024980