2857
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 2858
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 2856
- Möbius Function
- -1
- Radical
- 2857
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 172
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 415
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes p of the form 3k+1 such that sum_{x=1..p} cos(2*Pi*x^3/p) < -sqrt(p).at n=39A000923
- Numerators of Cotesian numbers (not in lowest terms): A002176(n)*C(n,0).at n=8A002177
- Primes p such that (p+1)/2 is prime.at n=42A005383
- Number of numerical semigroups of genus n; conjecturally also the number of power sum bases for symmetric functions in n variables.at n=15A007323
- Number of partitions of n in which no part occurs just once.at n=44A007690
- Array (a frieze pattern) defined by a(n,k) = (a(n-1,k)*a(n-1,k+1) - 1) / a(n-2,k+1), read by antidiagonals.at n=49A007754
- Primes p == 1 (mod 8), p = a^2 +64*b^2 such that y^2 = x^3 + p*x has rank 0.at n=10A007765
- Coordination sequence T2 for Zeolite Code DAC.at n=34A008068
- Number of partitions of n into at most 8 parts.at n=31A008637
- Coordination sequence for alpha-Mn, Position Mn1.at n=14A009950
- Numerator of [x^n] of the Taylor series log(arctan(x)/log(x+1)).at n=8A013570
- Numbers k such that the continued fraction for sqrt(k) has period 23.at n=8A020362
- Place where n-th 1 occurs in A023133.at n=42A022795
- n-th prime p(k) such that p(k) + p(k+9) = p(k+3) + p(k+6).at n=34A022893
- Primes that remain prime through 2 iterations of function f(x) = 2x + 3.at n=43A023242
- Primes that remain prime through 2 iterations of function f(x) = 4x + 9.at n=47A023251
- Primes that remain prime through 2 iterations of the function f(x) = 5x + 8.at n=30A023255
- Primes that remain prime through 2 iterations of the function f(x) = 8*x + 5.at n=22A023262
- Primes that remain prime through 3 iterations of function f(x) = 2x + 3.at n=13A023273
- Primes that remain prime through 3 iterations of function f(x) = 4x + 9.at n=12A023282