# Got guts?

#### anil

A prime number is a positive ineger greater than 2 whose only integer divisors are itself and 1. A Mersenne prime in of the form 2^(n) - 1 where p is a prime. For example 2^(5) - 1 = 31 is a Mersenne prime. One of the larger Mersenne prime is 2^(216091) - 1. Estimate the number of decimal digits in this number.

#### jcsd

Gold Member
Okay it's not my job to do your homework, so I will only give you a few pointers:

The -1 is unimortant to your estimate, so ignore that for the minute:

You can then construct this equation:

2^(216091) = 10^x

From here it should be very easy to solve.

#### anil

Kiddo: this is not my HW

This is not my homework. LoL this is a "challenge problem" they give in my college to exercise brain. I got the answer I just wanna see my asnwer is right. 72030

#### jcsd

Gold Member
No your answer is wrong, look at the equation I gave again, you may of made a simple error.

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