Primes, Prime Factors

About
This app lets you
• check numbers to see if they are prime numbers,
• find next prime,
• find primes within an interval (range), and
• determining prime factors.
The input numbers need be between 0 and 4,611,686,018,427,387,904, which is 2^62, or approximately 4.611·10^18. Just keep numbers less than 19 digits; a validation mechanism prevents illegal input.

Primes
A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself. Examples: 2, 3, 5, 7, 11, 13, 17. 2 is the only even prime.
When finding primes in an interval, duration is shown, so the app may be used for benchmarking as well.

Prime factor
A natural number greater than 1 that is not a prime number is called a composite number. Enter any number into the Factor field, to get its prime factors. If the number is a prime, then it has only one factor, itself.