2003
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 5
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 2004
- 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
- 2002
- Möbius Function
- -1
- Radical
- 2003
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 143
- 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
- yes
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 304
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes p == 3, 9, 11 (mod 20) such that 2p+1 is also prime.at n=30A000355
- Primes with 5 as smallest primitive root.at n=42A001124
- Lucasian primes: p == 3 (mod 4) with 2*p+1 prime.at n=31A002515
- Primes written in base 4.at n=31A004678
- Second (lower) diagonal of partition triangle A047812.at n=10A007045
- Primes of form 2n^2 - 2n + 19.at n=26A007639
- "Pascal sweep" for k=10: draw a horizontal line through the 1 at C(k,0) in Pascal's triangle; rotate this line and record the sum of the numbers on it (excluding the initial 1).at n=25A009550
- Coordination sequence T6 for Zeolite Code DFO.at n=34A009880
- Coordination sequence T4 for Zeolite Code RSN.at n=29A009888
- Number of commutative elements in Coxeter group F_n.at n=3A013980
- a(n) = n^2 - floor( n/2 ).at n=45A014848
- Smallest prime that begins with n.at n=19A018800
- Numbers k such that the continued fraction for sqrt(k) has period 30.at n=22A020369
- Primes that remain prime through 2 iterations of function f(x) = 8x + 9.at n=19A023264
- n written in fractional base 4/2.at n=19A024630
- n written in fractional base 6/2.at n=57A024635
- a(n) = Sum{T(i,j)}, 0<=j<=i, 0<=i<=n, T given by A026568.at n=8A026582
- a(n) = T(n,0) + T(n,1) + ... + T(n,2n), T given by A027113.at n=7A027115
- Palindromic primes in base 15.at n=27A029982
- a(n) is the least prime > a(n-1) whose digits do not appear in a(n-1).at n=19A030284