In recreational mathematics, a repunit is a number like 11, 111, or 1111 that contains only the digit 1 — a more specific type of repdigit. The term stands for repeated unit and was coined in 1966 by Albert H. Beiler in his book Recreations in the Theory of Numbers. [note 1] A repunit prime is a repunit that is also a prime number. By Euclid's theorem, there is an infinite number of prime numbers. Subsets of the prime numbers may be generated with various formulas for primes. The first 1,000 primes are listed below, followed by lists of notable types of prime numbers in alphabetical order, giving their respective first terms. The number 1 is neither prime nor composite. All numbers from 1 to 1000 are spinning and in 3D, with amazing backgrounds. -- Music by No Copyright Sounds (NCS), these are their ten best viewed songs as of September 2017. The number 1111111111111111111 can be divided by 2 positive divisors (out of which none is even, and 2 are odd). The sum of these divisors (counting 1111111111111111111) is 1111111111111111112, the average is 555555555555555556. Next: Prime Number. $1918$. Discover the secrets of 11,111,111,111,111,111,111 with our full breakdown of its prime factors, divisors, and mathematical properties. What are the properties of number 11111111111111111111? In this visualization, the outer ring segments show the relative proportions of its seven prime factors. 1,111,111,111,111,111,111 or R19 is a prime number between 1,111,111,111,111,111,001 and 1,111,111,111,111,112,000. 1,111,111,111,111,111,111 has 2 factors, 1 and 1,111,111,111,111,111,111. It is also the 2nd repunit prime number (19 one's), and 23rd permutable prime number. — Divisible by 1 —. Explore the video 111111111111111111111111111111111111111111111111111111111111111 on YouTube showcasing unique content and engaging visuals. Explore the hidden properties of 1111111111111111111, an odd prime number. Includes Prime Factorization, Divisors, Bases and Fun Facts for students, number lovers and curious minds. The first three, 11, 11 and 1111111111111111111, are palindromic primes. Note that the concatenation of these three palprimes is R (2).R (2).R (19) = R (23) = 11111111111111111111111.