2568
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
- 16
- Divisor Sum
- 6480
- Proper Divisor Sum (Aliquot Sum)
- 3912
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 848
- Möbius Function
- 0
- Radical
- 642
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 3
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
- 27
- Smith Number
- no
- Vampire 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
- yes
- Odd
- no
Appears in sequences
- A nonlinear binomial sum.at n=14A000126
- High temperature series for partition function for spin-1/2 Ising model on b.c.c. lattice.at n=4A001406
- Cluster series for bond percolation problem on hexagonal lattice.at n=5A003197
- Spiral sieve using Fibonacci numbers.at n=16A005623
- Let F(x) = 1 + x + 4x^2 + 9x^3 + ... = g.f. for A002835 (solid partitions restricted to two planes) and expand (1-x)*(1-x^2)*(1-x^3)*...*F(x) in powers of x.at n=13A005980
- a(n) = 3 + n/2 + 7*n^2/2.at n=27A006124
- Coordination sequence T11 for Zeolite Code MFI.at n=32A008163
- Numbers k such that phi(k) | sigma_13(k).at n=46A015771
- Coordination sequence T1 for Zeolite Code TER.at n=34A016433
- a(n) = Sum_{k=1..n} (n-k) * floor(n/k).at n=29A024920
- Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 19 (most significant digit on right).at n=21A029512
- Numbers with exactly five distinct base-7 digits.at n=14A031984
- Numbers k such that 147*2^k+1 is prime.at n=23A032423
- Numbers k such that 193*2^k+1 is prime.at n=21A032473
- Gozinta numbers: possible number of gozinta chains for some positive integer.at n=42A034776
- Smallest integer whose name in colloquial American English (no "and"s) uses n different letters.at n=16A038188
- Denominator of B(4n+2)/(8n+4) where B(m) are the Bernoulli numbers.at n=25A043304
- Numbers n such that string 1,0 occurs in the base 8 representation of n but not of n-1.at n=39A044195
- Numbers k such that the string 6,3 occurs in the base 9 representation of k but not of k-1.at n=34A044308
- Numbers n such that string 6,8 occurs in the base 10 representation of n but not of n-1.at n=27A044400