1020
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
- 24
- Divisor Sum
- 3024
- Proper Divisor Sum (Aliquot Sum)
- 2004
- 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
- 256
- Möbius Function
- 0
- Radical
- 510
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 4
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
- 49
- 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 positive integers <= 2^n of form x^2 + 16*y^2.at n=13A000018
- Number of ways of writing n as a sum of 6 squares.at n=8A000141
- Double-bitters: only even length runs in binary expansion.at n=30A001196
- a(1)=0, a(2n) = a(n)+1, a(2n+1) = 10*a(n+1).at n=38A001202
- Expansion of 1/((1-x^2)*(1-x^4)^2*(1-x^6)*(1-x^8)*(1-x^10)) (even powers only).at n=23A001994
- In the pile of coconuts problem, the number of coconuts that remain to be shared equally at the end of the process.at n=3A002022
- Numbers of edges of regular polygons constructible with ruler (or, more precisely, an unmarked straightedge) and compass.at n=54A003401
- Convolution of Fibonacci numbers 1,2,3,5,... with themselves.at n=9A004798
- Number of nonequivalent dissections of a polygon into n heptagons by nonintersecting diagonals up to rotation and reflection.at n=5A005419
- Number of Twopins positions.at n=18A005691
- a(n) is the smallest positive integer a for which there is an identity of the form a*n*x = Sum_{i=1..m} ai*gi(x)^n where a1, ..., am are in Z and g1(x), ..., gm(x) are in Z[x].at n=17A005729
- Numbers not of form p + 2^x + 2^y.at n=20A006286
- Number of nonseparable toroidal tree-rooted maps with n + 3 edges and n + 1 vertices.at n=2A006415
- From generalized Catalan numbers.at n=4A006630
- Numbers in base 3.at n=33A007089
- McKay-Thompson series of class 5a for Monster.at n=13A007253
- Numbers k such that sigma(x) = k has exactly 3 solutions.at n=26A007372
- Moebius transform of triangular numbers.at n=51A007438
- Integers written in factorial base.at n=28A007623
- Some permutation of digits is a factorial number.at n=25A007926