When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. 21 (number) - Wikipedia

    en.wikipedia.org/wiki/21_(number)

    There are 21 prime numbers with 2 digits. There are A total of 21 prime numbers between 100 and 200. 21 is the first Blum integer, since it is a semiprime with both its prime factors being Gaussian primes. [3] While 21 is the sixth triangular number, [4] it is also the sum of the divisors of the first five positive integers:

  3. Divisor - Wikipedia

    en.wikipedia.org/wiki/Divisor

    This article includes a list of general ... 14, 21, 42. The set of all positive divisors of 60, = {,, ... Table of prime factors – A table of prime factors for 1 ...

  4. Table of prime factors - Wikipedia

    en.wikipedia.org/wiki/Table_of_prime_factors

    All integers are either even or odd. A square has even multiplicity for all prime factors (it is of the form a 2 for some a). The first: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144 (sequence A000290 in the OEIS). A cube has all multiplicities divisible by 3 (it is of the form a 3 for some a).

  5. Table of divisors - Wikipedia

    en.wikipedia.org/wiki/Table_of_divisors

    The tables below list all of the divisors of the numbers 1 to 1000. A divisor of an integer n is an integer m, for which n / m is again an integer (which is necessarily also a divisor of n). For example, 3 is a divisor of 21, since 21/7 = 3 (and therefore 7 is also a divisor of 21). If m is a divisor of n, then so is − m.

  6. Prime number - Wikipedia

    en.wikipedia.org/wiki/Prime_number

    A prime number (or a prime) is a natural number greater than 1 that is not a product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime because the only ways of writing it as a product, 1 × 5 or 5 × 1, involve 5 itself. However, 4 is composite because it is a ...

  7. List of prime numbers - Wikipedia

    en.wikipedia.org/wiki/List_of_prime_numbers

    All prime numbers from 31 to 6,469,693,189 for free download. Lists of Primes at the Prime Pages. The Nth Prime Page Nth prime through n=10^12, pi(x) through x=3*10^13, Random primes in same range. Interface to a list of the first 98 million primes (primes less than 2,000,000,000) Weisstein, Eric W. "Prime Number Sequences". MathWorld.

  8. Integer factorization - Wikipedia

    en.wikipedia.org/wiki/Integer_factorization

    Every positive integer greater than 1 is either the product of two or more integer factors greater than 1, in which case it is called a composite number, or it is not, in which case it is called a prime number. For example, 15 is a composite number because 15 = 3 · 5, but 7 is a prime number because it cannot be decomposed in this way.

  9. Fibonacci prime - Wikipedia

    en.wikipedia.org/wiki/Fibonacci_prime

    That is to say, the Fibonacci sequence is a divisibility sequence. Fp is prime for 8 of the first 10 primes p; the exceptions are F2 = 1 and F19 = 4181 = 37 × 113. However, Fibonacci primes appear to become rarer as the index increases. Fp is prime for only 26 of the 1229 primes p smaller than 10,000. [3] The number of prime factors in the ...