1993
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 1994
- 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
- 1992
- Möbius Function
- -1
- Radical
- 1993
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 50
- 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
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 301
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes with 5 as smallest primitive root.at n=41A001124
- Class 4+ primes (for definition see A005105).at n=33A005108
- Primes p such that (p+1)/2 is prime.at n=34A005383
- Where the prime race among 7k+1, ..., 7k+6 changes leader.at n=18A007354
- Prime triples: p; p+2 or p+4; p+6 all prime.at n=48A007529
- Sum along upward diagonal of Pascal triangle to center.at n=17A010752
- Sum along upward diagonal of Pascal triangle up to (but not including) center.at n=17A010753
- a(n) = floor( n*(n-1)*(n-2)/11 ).at n=29A011893
- Numbers in which every prefix (in base 10) is 1 or a prime.at n=51A012883
- 3 and -3 are both 4th powers (one implies other) mod these primes p=1 mod 8.at n=13A014755
- a(n) = 2^n - n*(n-1)/2.at n=11A014844
- Eight iterations of Reverse and Add are needed to reach a palindrome.at n=10A015988
- Number of partitions of n into parts having a common factor.at n=50A018783
- Let Dedekind's psi(m) = product of (p+1)p^(e-1) for primes p, where p^e is a factor of m. Iterating psi(m) eventually results in a number of form 2^a*3^b. a(n) is the smallest number that requires n steps to reach such a number.at n=6A019268
- Numbers k such that the continued fraction for sqrt(k) has period 47.at n=1A020386
- Initial members of prime triples (p, p+4, p+6).at n=25A022005
- Number of solutions to c(1)*prime(3)+...+c(n)*prime(n+2) = 2, where c(i) = +-1 for i>1, c(1) = 1.at n=19A022902
- Primes that remain prime through 2 iterations of function f(x) = 9x + 2.at n=31A023265
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = A023532, t = A001950 (upper Wythoff sequence).at n=49A025074
- Index of 7^n within the sequence of the numbers of the form 2^i*7^j.at n=37A025720