2387
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 3072
- Proper Divisor Sum (Aliquot Sum)
- 685
- 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
- 1800
- Möbius Function
- -1
- Radical
- 2387
- Omega Function (Ω)
- 3
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 102
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- Divisors of 2^30 - 1.at n=28A003538
- a(n) = n*(5*n - 1)/2.at n=31A005476
- Oscillates under partition transform.at n=37A007210
- Coordination sequence T2 for Zeolite Code BRE.at n=32A008059
- Coordination sequence T2 for Zeolite Code FER.at n=30A008107
- Coordination sequence T4 for Zeolite Code TON.at n=30A008244
- Coordination sequence for FeS2-Marcasite, S position.at n=24A009954
- Positive numbers k such that k and 3*k are anagrams in base 9 (written in base 9).at n=26A023080
- Convolution of natural numbers with Beatty sequence for the golden mean A000201.at n=19A023541
- Quasi-Carmichael numbers to base -7: squarefree composites n such that prime p|n ==> p+7|n+7.at n=2A029567
- All slopes (a(n)-a(m))/(n-m) are distinct; generated from 0 by greedy algorithm.at n=43A033808
- Numerators of continued fraction convergents to sqrt(271).at n=4A041508
- Numbers n such that lcm(sigma(n),phi(n)) is a perfect square.at n=20A043293
- Numbers n such that string 4,2 occurs in the base 9 representation of n but not of n-1.at n=32A044289
- Numbers n such that string 8,7 occurs in the base 10 representation of n but not of n-1.at n=25A044419
- Numbers n such that string 4,2 occurs in the base 9 representation of n but not of n+1.at n=32A044670
- Numbers k such that string 8,7 occurs in the base 10 representation of k but not of k+1.at n=25A044800
- T(n,n-3), array T as in A047060.at n=6A047065
- Number of nonempty subsets of {1,2,...,n} in which exactly 1/4 of the elements are <= (n-1)/2.at n=15A047174
- Number of nonempty subsets of {1,2,...,n} in which exactly 1/4 of the elements are <= (n-2)/2.at n=15A047185