4691
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
- 4692
- 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
- 4690
- Möbius Function
- -1
- Radical
- 4691
- 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
- 152
- 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
- 634
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(0) = 1, a(n) = 5 + Product_{i=0..n-1} a(i) for n > 0.at n=4A001543
- Artiads: the primes p == 1 (mod 5) for which Fibonacci((p-1)/5) is divisible by p.at n=26A001583
- Expansion of 1/((1-x^2)*(1-x^4)^2*(1-x^6)*(1-x^8)*(1-x^10)) (even powers only).at n=34A001994
- Primes of the form k^2 - k - 1.at n=38A002327
- Balanced primes (of order one): primes which are the average of the previous prime and the following prime.at n=38A006562
- Apply partial sum operator twice to Stern's sequence.at n=12A014172
- Numbers k such that the continued fraction for sqrt(k) has period 78.at n=5A020417
- Primes that remain prime through 2 iterations of function f(x) = 8x + 1.at n=16A023260
- 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 67.at n=19A031565
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 38 ones.at n=15A031806
- Primes of form x^2+95*y^2.at n=34A033206
- Number of partitions of n with equal nonzero number of parts congruent to each of 2 and 3 (mod 5).at n=40A035569
- Positive numbers having the same set of digits in base 5 and base 8.at n=30A037431
- Discriminants of imaginary quadratic fields with class number 21 (negated).at n=13A046018
- Sequence of 2 Pythagorean triangles, each with a leg and hypotenuse prime. The leg of the second triangle is the hypotenuse of the first.at n=19A048270
- Primes p such that pp'-2 is prime, where p' denotes the next prime after p.at n=25A048797
- Primes p such that p-12, p and p+12 are consecutive primes.at n=3A053072
- Number of primitive (period n) bracelet structures using a maximum of five different colored beads.at n=10A056364
- a(n+1) = smallest prime p in the range a(n) < p < a(1)*a(2)*...*a(n) such that p-1 divides a(1)*a(2)*...*a(n); or if no such prime p exists, then a(n+1) = smallest prime > a(n).at n=43A057459
- Primes p such that x^67 = 2 has no solution mod p.at n=9A059330