3917
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
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 3918
- 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
- 3916
- Möbius Function
- -1
- Radical
- 3917
- 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
- 51
- 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
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 542
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Coordination sequence T2 for Zeolite Code NES.at n=40A008206
- Coordination sequence T6 for Zeolite Code NES.at n=40A008210
- Coordination sequence T2 for Moganite, also for BGB1.at n=40A008259
- Coordination sequence T3 for Zeolite Code TER.at n=42A016435
- Numbers k such that the continued fraction for sqrt(k) has period 41.at n=7A020380
- Let q_k=p(p+2) be product of k-th pair of twin primes; sequence gives values of p such that (q_k)^2 > q_{k-i}q_{k+i} for all 1 <= i <= k-1.at n=33A021005
- Initial members of prime triples (p, p+2, p+6).at n=33A022004
- Primes that remain prime through 3 iterations of function f(x) = 4x + 3.at n=13A023281
- a(n) = least m such that if r and s in {1/1, 1/2, 1/3, ..., 1/n} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.at n=47A024833
- Smallest prime in Goldbach partition of A025018(n).at n=47A025019
- a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026780.at n=4A027250
- a(n) = floor(n^3 / e).at n=22A032636
- Primes of form x^2+77*y^2.at n=27A033249
- Number of partitions of n into parts not of the form 7k, 7k+3 or 7k-3. Also number of partitions such that the differences between parts at distance 2 are greater than 1.at n=43A035939
- Denominators of continued fraction convergents to sqrt(881).at n=8A042703
- Second member of a sexy prime quadruple: value of p+6 such that p, p+6, p+12 and p+18 are all prime.at n=15A046122
- Primes of the form k^2 + k + 11.at n=34A048059
- a(n) = Sum_{i=0..2n} (-1)^i * T(i,2n-i), array T as in A049747.at n=45A049749
- Inserting any digit between adjacent digits of prime p produces exactly 1 new prime.at n=44A050806
- Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 13.at n=16A050962