31 and Mersenne Primes - Numberphile
31 is one of the special Mersenne Prime numbers. They are related to perfect numbers. More links & stuff in full description below ↓↓↓ See our perfect number video at http://www.youtube.com...
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JAMES GRIME: OK, so today we're going to talk Mersenne numbers. So we have to pick one of our Mersenne numbers to exemplify the category. Now, Brady always makes me do this, so I've decided to pick 31, because by the time you watch this video, I will be 31. So it's a nice personal number for me. So 31 is our example of a Mersenne prime. So a Mersenne prime is a prime number to begin with like 31. 31 is a prime number. A prime number is, as you probably know, a number that can only be divided by 1 and itself. The first few prime numbers are 2, 3, 5, 7. 31 is a prime number, but it's a special type of prime number because it's one less than a power of 2. What are the powers of 2? Well, you've got 2. You've got 4. ...
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JAMES GRIME: OK, so today we're going to talk Mersenne numbers. So we have to pick one of our Mersenne numbers to exemplify the category. Now, Brady always makes me do this, so I've decided to pick 31, because by the time you watch this video, I will be 31. So it's a nice personal number for me. So 31 is our example of a Mersenne prime. So a Mersenne prime is a prime number to begin with like 31. 31 is a prime number. A prime number is, as you probably know, a number that can only be divided by 1 and itself. The first few prime numbers are 2, 3, 5, 7. 31 is a prime number, but it's a special type of prime number because it's one less than a power of 2. What are the powers of 2? Well, you've got 2. You've got 4. ...
