1569
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 2096
- Proper Divisor Sum (Aliquot Sum)
- 527
- 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
- 1044
- Möbius Function
- 1
- Radical
- 1569
- 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
- 34
- 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
- Number of connected functions on n labeled nodes.at n=4A001865
- Sums of distinct nonzero 4th powers.at n=42A003999
- Coordination sequence T2 for Zeolite Code BRE.at n=26A008059
- Coordination sequence T1 for Zeolite Code MTW.at n=26A008196
- Coordination sequence T2 for Zeolite Code THO.at n=28A008239
- Coordination sequence T7 for Zeolite Code CON.at n=28A009874
- Numbers k such that the continued fraction for sqrt(k) has period 46.at n=7A020385
- a(n) = [ a(n-1)/a(1) ] + [ a(n-2)/a(2) ] + ... + [ a(1)/a(n-1) ], for n >= 3.at n=14A022858
- Numbers k such that Fibonacci(k) == -2 (mod k).at n=24A023163
- a(n) = position of 5 + n^2 in A004432.at n=42A024808
- a(n) = position of n^2 + (n+1)^2 + (n+2)^2 in A004432.at n=24A024809
- a(n) = position of 3*n^2 in sequence A025051 (numbers of form j*k + k*i + i*j, without repetitions, where 1 <= i <= j <= k).at n=22A025056
- a(n) = n^2 + n + 9.at n=39A027694
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 26.at n=12A031524
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 22 ones.at n=7A031790
- Numbers whose set of base-6 digits is {1,3}.at n=33A032913
- Fractional part of square root of a(n) starts with 6: first term of runs.at n=37A034112
- Sum of the lengths of the cycle types of the permutation created by length sorting on the partitions of n.at n=23A036056
- Denominators of continued fraction convergents to sqrt(271).at n=7A041509
- Numerators of continued fraction convergents to sqrt(785).at n=1A042512