12991541 has 2 divisors, whose sum is σ = 12991542. Its totient is φ = 12991540.

The previous prime is 12991523. The next prime is 12991543. The reversal of 12991541 is 14519921.

12991541 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8702500 + 4289041 = 2950^2 + 2071^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12991541 is a prime.

Together with 12991543, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 12991498 and 12991507.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12991543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6495770 + 6495771.

It is an arithmetic number, because the mean of its divisors is an integer number (6495771).

Almost surely, 2^12991541 is an apocalyptic number.

It is an amenable number.

12991541 is a deficient number, since it is larger than the sum of its proper divisors (1).

12991541 is an equidigital number, since it uses as much as digits as its factorization.

12991541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3240, while the sum is 32.

The square root of 12991541 is about 3604.3780323379. The cubic root of 12991541 is about 235.0824578599.

The spelling of 12991541 in words is "twelve million, nine hundred ninety-one thousand, five hundred forty-one".