2571
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 3432
- Proper Divisor Sum (Aliquot Sum)
- 861
- 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
- 1712
- Möbius Function
- 1
- Radical
- 2571
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 53
- 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 that are the sum of 9 positive 6th powers.at n=33A003365
- Numbers that are the sum of 4 positive 7th powers.at n=8A003371
- Numbers that are the sum of at most 4 positive 7th powers.at n=24A004866
- Numbers that are the sum of at most 5 positive 7th powers.at n=33A004867
- Numbers that are the sum of at most 6 positive 7th powers.at n=43A004868
- Coordination sequence T3 for Zeolite Code AFS and BPH.at n=39A008025
- G.f.: (1+x)*(1+x^3)*(1+x^5)*(1+x^7)*(1+x^9)/((1-x^2)*(1-x^4)*(1-x^6)*(1-x^8)*(1-x^10)).at n=49A014670
- Coordination sequence T3 for Zeolite Code TER.at n=34A016435
- Powers of cube root of 19 rounded up.at n=8A018032
- Numbers k such that the continued fraction for sqrt(k) has period 38.at n=24A020377
- Fibonacci sequence beginning 3, 16.at n=12A022126
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (F(2), F(3), ...), t = (primes).at n=15A024597
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (F(2), F(3), F(4), ...), t = (primes).at n=14A025111
- 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 49.at n=15A031547
- Lucky numbers with size of gaps equal to 8 (upper terms).at n=26A031891
- Fractional part of square root of a(n) starts with 7: first term of runs.at n=48A034113
- Nonprime; becomes prime if any digit is deleted (zeros not allowed in the number).at n=36A034304
- Number of partitions of n into parts 5k+1 or 5k+3.at n=54A035372
- Number of partitions satisfying cn(1,5) <= 1 and cn(4,5) <= 1.at n=35A039854
- Smallest number k for which k, 2k, ... nk all contain the digit 1.at n=4A039932