1828
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
- 3
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 3206
- Proper Divisor Sum (Aliquot Sum)
- 1378
- 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
- 912
- Möbius Function
- 0
- Radical
- 914
- Omega Function (Ω)
- 3
- 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
- 130
- 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
- Number of binary partitions: number of partitions of 2n into powers of 2.at n=32A000123
- Numbers k such that 57*2^k + 1 is prime.at n=21A002274
- Number of partitions of 2^n into powers of 2.at n=6A002577
- Convolution of A002024 with itself.at n=47A004797
- Representation degeneracies for boson strings.at n=23A005293
- Closed meandric numbers (or meanders): number of ways a loop can cross a road 2n times.at n=6A005315
- Meandric numbers: number of ways a river can cross a road n times.at n=11A005316
- Coordination sequence T2 for Zeolite Code BRE.at n=28A008059
- Coordination sequence T11 for Zeolite Code MFI.at n=27A008163
- Triangle read by rows: T(n,k) = number of closed meander systems of order n with k<=n components.at n=15A008828
- Expansion of e.g.f.: tanh(log(1+tanh(x))).at n=7A009774
- Coordination sequence T1 for Zeolite Code -CHI.at n=27A009846
- Coordination sequence T7 for Zeolite Code VNI.at n=26A009913
- Coordination sequence for MgZn2, Position Zn1.at n=11A009937
- a(n) = floor(binomial(n,4)/4).at n=22A011850
- a(n) = n^2 - floor( n/2 ).at n=43A014848
- Powers of cube root of 5 rounded to nearest integer.at n=14A017989
- Powers of cube root of 5 rounded up.at n=14A017990
- Number of partitions of n into divisors of n.at n=63A018818
- Numbers k such that the continued fraction for sqrt(k) has period 46.at n=8A020385