nope that ain't it guess again

what is your problem? stop posting mindless junk!

Stop.

1511

1523

1531

The smallest prime that is also a sum of primes beginning and ending with the digit seven (1531 = 7 + 727 + 797). Well, excluding the degenerate case of 7 by itself...

1543

1549

The smallest odd number that is not the sum of a prime and a power > 1 (!)

For examples:
1543 = 1511 + 2^5
1531 = 1523 + 2^3
1523 = 1459 + 8^2

... but no such equation for 1549.

1553
@above BearofNH
are you doing any master cource in prime numbrs????

1559

As we all know, every number is interesting. I'm just pointing out some of the reasons why.

But yes, I did my master's in number theory very long ago. I studied under Gauss.

1567
that's gr8......

1571

1579

1583

1597

1601

1607

1609

1613

1619

1621

There are 98 million primes less than 2000000000, so we could be here for a while :-)

1627

1637

1657

Third of 3 primes in a row, all ending in 7

OK, I am new to this, but is there a simple test for a number being prime? The number obviously cannot end in an even number or with a five or a zero. So we eliminate testing division by 2, 4, 5, 6, 8, and 10 immediately. Any number divisible by 9 is also divisible by 3, so it seems the first tests are to find if the next number is divisible by 3, 7, 11, 13, 17, etc., to include other prime numbers as we progress. Does this make sense?

It seems that 1667 is the next number that passes these tests.

It seems that 1667 is the next number that passes these tests.

Actually I thought the next one would be 1663.

1669 is the next after 1667

A big jump to the next one which is .....

1693

small jump of four to 1697

An even smaller jump... 1699

1709

This topic has been dead for over six months. Start a new discussion instead.
Have something to contribute to this discussion? Please be thoughtful, detailed and courteous, and be sure to adhere to our posting rules.