Large 2-digit numbers that factor into 2-digit numbers.
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$799777779779979$ and $111111811818111$ are numbers of $2$ non-zero digits that can be factored into $2$-digit numbers. They are $97$-smooth numbers.
Are there any larger examples?
combinatorics number-theory recreational-mathematics prime-factorization
edited Nov 22 at 12:57
Klangen
1,43711232
asked Feb 3 '17 at 21:49
Ed Pegg
9,73432591
add a comment |
up vote
5
down vote
favorite
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$799777779779979$ and $111111811818111$ are numbers of $2$ non-zero digits that can be factored into $2$-digit numbers. They are $97$-smooth numbers.
Are there any larger examples?
combinatorics number-theory recreational-mathematics prime-factorization
edited Nov 22 at 12:57
Klangen
1,43711232
asked Feb 3 '17 at 21:49
Ed Pegg
9,73432591
1
"numbers of 2 non-zero digits" means what?
– Thomas Andrews
Feb 3 '17 at 22:05
1
Note that "friable" is a more descriptive and more modern term than the conventional "smooth" in this context.
– Greg Martin
Feb 3 '17 at 22:05
1
According to my calculation, a larger example must have more than $20$ digits. The ratio of smooth numbers decreases drastically , so it is well possible that no larger example exists.
– Peter
Feb 4 '17 at 21:53
add a comment |
up vote
5
down vote
favorite
3
up vote
5
down vote
favorite
3
3
$799777779779979$ and $111111811818111$ are numbers of $2$ non-zero digits that can be factored into $2$-digit numbers. They are $97$-smooth numbers.
Are there any larger examples?
combinatorics number-theory recreational-mathematics prime-factorization
edited Nov 22 at 12:57
Klangen
1,43711232
asked Feb 3 '17 at 21:49
Ed Pegg
9,73432591
$799777779779979$ and $111111811818111$ are numbers of $2$ non-zero digits that can be factored into $2$-digit numbers. They are $97$-smooth numbers.
Are there any larger examples?
combinatorics number-theory recreational-mathematics prime-factorization
combinatorics number-theory recreational-mathematics prime-factorization
edited Nov 22 at 12:57
Klangen
1,43711232
asked Feb 3 '17 at 21:49
Ed Pegg
9,73432591
edited Nov 22 at 12:57
Klangen
1,43711232
asked Feb 3 '17 at 21:49
Ed Pegg
9,73432591
edited Nov 22 at 12:57
Klangen
1,43711232
edited Nov 22 at 12:57
Klangen
1,43711232
edited Nov 22 at 12:57
Klangen
1,43711232
1,43711232
asked Feb 3 '17 at 21:49
Ed Pegg
9,73432591
asked Feb 3 '17 at 21:49
Ed Pegg
9,73432591
asked Feb 3 '17 at 21:49
Ed Pegg
9,73432591
9,73432591
1
"numbers of 2 non-zero digits" means what?
– Thomas Andrews
Feb 3 '17 at 22:05
1
Note that "friable" is a more descriptive and more modern term than the conventional "smooth" in this context.
– Greg Martin
Feb 3 '17 at 22:05
1
According to my calculation, a larger example must have more than $20$ digits. The ratio of smooth numbers decreases drastically , so it is well possible that no larger example exists.
– Peter
Feb 4 '17 at 21:53
add a comment |
1
"numbers of 2 non-zero digits" means what?
– Thomas Andrews
Feb 3 '17 at 22:05
1
Note that "friable" is a more descriptive and more modern term than the conventional "smooth" in this context.
– Greg Martin
Feb 3 '17 at 22:05
1
According to my calculation, a larger example must have more than $20$ digits. The ratio of smooth numbers decreases drastically , so it is well possible that no larger example exists.
– Peter
Feb 4 '17 at 21:53
1
1
"numbers of 2 non-zero digits" means what?
– Thomas Andrews
Feb 3 '17 at 22:05
"numbers of 2 non-zero digits" means what?
– Thomas Andrews
Feb 3 '17 at 22:05
1
1
Note that "friable" is a more descriptive and more modern term than the conventional "smooth" in this context.
– Greg Martin
Feb 3 '17 at 22:05
Note that "friable" is a more descriptive and more modern term than the conventional "smooth" in this context.
– Greg Martin
Feb 3 '17 at 22:05
1
1
According to my calculation, a larger example must have more than $20$ digits. The ratio of smooth numbers decreases drastically , so it is well possible that no larger example exists.
– Peter
Feb 4 '17 at 21:53
According to my calculation, a larger example must have more than $20$ digits. The ratio of smooth numbers decreases drastically , so it is well possible that no larger example exists.
– Peter
Feb 4 '17 at 21:53
add a comment |
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1
"numbers of 2 non-zero digits" means what?
– Thomas Andrews
Feb 3 '17 at 22:05
1
Note that "friable" is a more descriptive and more modern term than the conventional "smooth" in this context.
– Greg Martin
Feb 3 '17 at 22:05
1
According to my calculation, a larger example must have more than $20$ digits. The ratio of smooth numbers decreases drastically , so it is well possible that no larger example exists.
– Peter
Feb 4 '17 at 21:53