4871
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
- 4872
- 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
- 4870
- Möbius Function
- -1
- Radical
- 4871
- 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
- 46
- 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
- 652
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Artiads: the primes p == 1 (mod 5) for which Fibonacci((p-1)/5) is divisible by p.at n=28A001583
- a(1) = 1, a(n) = Sum_{k=1..n-1} Sum_{d|k} a(d).at n=12A014668
- Powers of fourth root of 2 rounded to nearest integer.at n=49A018049
- Powers of fourth root of 2 rounded up.at n=49A018050
- Numbers k such that the continued fraction for sqrt(k) has period 68.at n=9A020407
- Numbers whose least quadratic nonresidue (A020649) is 11.at n=29A025024
- Primes which when concatenated with next 3 primes are also prime.at n=36A030472
- 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=10A031567
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 30 ones.at n=36A031798
- Number of partitions satisfying (cn(2,5) <= cn(1,5) and cn(3,5) <= cn(1,5) and cn(2,5) <= cn(4,5) and cn(3,5) <= cn(4,5)).at n=37A036802
- Primes of the form n*phi(n)-1 where phi is the Euler function (in order of appearance).at n=37A046078
- a(n) = a(n-1) + a(m) for n >= 4, where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = a(2) = 1 and a(3) = 3.at n=42A050033
- Primes p from A031924 such that A052180(primepi(p)) = 11.at n=12A052232
- Least prime in A031924 (lesser of 6-twins) such that the distance to the next 6-twin is 2*n.at n=13A052352
- Primes q of the form q = 10p + 1, where p is also prime.at n=22A055781
- Smallest prime divisor of Kummer numbers ( = primorials - 1), or 1 if no such prime exists.at n=33A057713
- Primes p such that x^5 == 2 (mod p) has five solutions.at n=30A059858
- Primes with 11 as smallest positive primitive root.at n=23A061324
- Group successively larger prime numbers so that the sum of the n-th group is a multiple of n. Sequence gives the first term of each group.at n=38A074129
- Primes p such that sum of squares of even-position digits equals the sum of squares of odd-position digits of p.at n=2A076168