# Tag Info

Accepted

### Making the number 12345...n

FromDigits@Flatten[IntegerDigits /@ Range[15]] 123456789101112131415 A function to do it: ...
• 11.9k
Accepted

### Checking if a number is right sorted

f1 = OrderedQ @* Rest @* IntegerDigits; f1 /@ {51369, 51396} {True, False} ...
• 396k

### Making the number 12345...n

f1 = FromDigits @ StringRiffle[Range[#], ""] &; f1 /@ {4, 10, 15} {1234, 12345678910, 123456789101112131415} ...
• 396k

### Is there a command that does exact numerical conversion of non-exact to exact numbers?

However, the only method I've found that ensures numerically exact conversion is the manual one: delete the decimal point, and then divide by 10^z, where z is the number of digits to the right of the ...
• 235k
Accepted

### Exporting large numbers to .PDF file

One way would be to split the large number in smaller chunks, convert each of them to a string, which can be manipulated, and then exporting. ...

### How to plot a function with huge numbers?

Since we are dealing with very large numbers, so one of the option is to use ListLogPlot ...
• 11.9k

### Can I use NextPrime[n] up to n=10^14?

NextPrime has no problems evaluating for large numbers well above $10^{14}$. I think it's safe to assume these are real prime numbers, for confirmation see the ...
• 36.5k

### How to get the bit size (bit length) of an integer?

You can use BitLength or IntegerLength: BitLength[number] 4091 ...
• 396k

### Making the number 12345...n

Without using IntegerDigits or string processing: ...
• 25.3k

### Can I use NextPrime[n] up to n=10^14?

The prime generator and the primality proving package both seem very quick at $10^{14}$: ...
• 47.5k
Accepted

### Using the solve function for big numbers, getting a failure now

Hmm, I just posted an answer yesterday that overcame just this problem with the undocumented option "SolveDiscreteSolutionBound" that controls a system limit: <...
• 236k
Accepted

### Efficiently checking whether a number is a perfect power

I offer the following as a fast way of testing cubic and higher powers primes = Select[Range[59], PrimeQ] Get a list of all the relevant powers up to a specified ...
• 16.8k

### Checking if a number is right sorted

f = AllTrue[Rest[Differences[IntegerDigits[#]]], Positive] & Test: f /@ {51369, 412345, 824699, 41395, 31832} True, True, ...
• 54.3k

### How to stop calculating if there're some large number?

Here's one way, using Carl Woll's suggestion of MemoryConstrained, which runs very quickly: ...
• 236k
Accepted

### Why $\pi$ // Rationalize does not give a rational multiple of $\pi$ in my example?

I want to show that without hypotheses, the problem of determining whether $x=a/\pi$ came from a rational number is unsolvable. But, spoiler alert, the OP's number ...
• 236k

### Efficiently checking whether a number is a perfect power

There is this way: ...
• 20.3k

### Making the number 12345...n

ToExpression[ StringJoin[ ToString /@ Range[15] ] ]

### Making the number 12345...n

For fun, here's some more options, which are quite distinct from the already existing ones. First, a recursive definition: ...

### Making the number 12345...n

Timings for all the methods (g1 : murray, g2 : flinty, g3/g4 : AccidentalFourierTransform, g5/g6 : Syed, g7 : David Reiss, g8 : user1066, g9/g10/g11 : kglr) posted so far: ...
• 396k

### Performance regression for big integer computation

I think the best you can do, is to compile a function for BigInts with FunctionCompile. The compilation is slow, but the execution is fast: ...
• 23.5k
Accepted

### Solving an equation in integers giving an error message

This uses less memory: ...
• 236k
Accepted

• 41.2k

### Making the number 12345...n

Identical to the solution by @murray but written as a composition: f = FromDigits@* Flatten@* IntegerDigits@* Range@ # & f /@ Range[8, 15] ...
• 54.3k

### Checking if a number is right sorted

A slight variation on the method given by @kglr 51369//IntegerDigits[#,10,IntegerLength[#]-1]&//OrderedQ (* True *)
• 18.3k
Accepted

### How can I make sure that the two given numbers are exactly the same?

Code (explanation below) n2[[1 ;; 3]]*n2[[4]] == n2 (* True *) ...
• 5,882