2001
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 3
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 2880
- Proper Divisor Sum (Aliquot Sum)
- 879
- 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
- 1232
- Möbius Function
- -1
- Radical
- 2001
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 50
- 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
- Number of partitions into non-integral powers.at n=22A000148
- a(1)=0, a(2n) = a(n)+1, a(2n+1) = 10*a(n+1).at n=49A001202
- a(1) = 0, a(2) = 0; for n > 2, a(n) - a(n-3) - a(n-5) - ... - a(n-p) = n if n is prime, otherwise = 0, where p = largest prime < n.at n=28A002123
- Reverse digits of number of partitions of n.at n=22A004089
- Fibonacci numbers written in base 3.at n=10A004686
- a(n) = (n + 3)*(n^2 + 6*n + 2)/6.at n=20A005286
- a(n) = solution to the postage stamp problem with n denominations and 8 stamps.at n=6A005343
- Integers written in factorial base.at n=49A007623
- Some permutation of digits is a factorial number.at n=28A007926
- Some nontrivial permutation of digits is a factorial number.at n=22A007927
- Coordination sequence T1 for Zeolite Code LTN.at n=31A008140
- Coordination sequence T3 for Zeolite Code LTN.at n=31A008142
- Coordination sequence T4 for Zeolite Code NON.at n=27A008215
- Numbers k such that k^2 and k have same last 3 digits.at n=9A008853
- E.g.f. log(1+x)/cos(x).at n=7A009429
- Partial sums of A003136.at n=39A014146
- Representation of n in base of Catalan numbers (a classic greedy version).at n=29A014418
- Coordination sequence T2 for Zeolite Code SAO.at n=35A019572
- Coordination sequence T3 for Zeolite Code SAO.at n=35A019573
- Pseudoprimes to base 70.at n=16A020198