4943
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
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 4944
- 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
- 4942
- Möbius Function
- -1
- Radical
- 4943
- 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
- 134
- 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
- 661
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes with 7 as smallest primitive root.at n=42A001126
- Primes of form 3*k^2 - 3*k + 23.at n=35A007637
- Numbers k such that the continued fraction for sqrt(k) has period 56.at n=19A020395
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (Fibonacci numbers), t = (1, p(1), p(2), ...).at n=19A024460
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (Fibonacci numbers), t = (primes).at n=18A024468
- Duplicate of A024468.at n=18A025080
- Primes p such that digits of p appear in p^2 and p^3.at n=28A030085
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 69.at n=17A031567
- Numbers whose set of base-13 digits is {2,3}.at n=21A032813
- Primes of form x^2+86*y^2.at n=26A033255
- a(n) = a(n-1) + a(m) for n >= 4, where m = 2*n - 2 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = a(2) = a(3) = 1.at n=30A050027
- 4th term in Euclid-Mullin prime sequence started with n-th prime (cf. A000945).at n=70A051614
- Least prime in A031926 (lesser of 8-twins) whose distance to the next 8-twin is 6*n.at n=16A052353
- Fourth term of weak prime quintets: p(m-2)-p(m-3) < p(m-1)-p(m-2) < p(m)-p(m-1) < p(m+1)-p(m).at n=12A054826
- Let prime(i) = i-th prime, let twin(n) = (P,Q) be n-th pair of twin primes; sequence gives prime(Q).at n=29A057473
- a(n) = n*(94 + 5*n + 25*n^2 - 5*n^3 + n^4)/120.at n=15A057703
- Numbers k such that k, 2*k+1, 3*k+2 are primes.at n=33A067256
- Primes in which the k-th digit (counting from the right) is either a nonzero multiple of k or a divisor of k; furthermore the digit 1 is allowed only when k has no other divisors < 10.at n=49A069556
- a(n) = prime(k) where k = n-th prime congruent to 1 mod 10.at n=28A078656
- Smallest prime p such that the backward concatenation of n consecutive decreasing primes starting with p is a prime.at n=40A083472