12917581 has 2 divisors, whose sum is σ = 12917582. Its totient is φ = 12917580.

The previous prime is 12917573. The next prime is 12917599. The reversal of 12917581 is 18571921.

It is a happy number.

12917581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10465225 + 2452356 = 3235^2 + 1566^2 .

It is an emirp because it is prime and its reverse (18571921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12917581 - 2³ = 12917573 is a prime.

It is a super-2 number, since 2×12917581² = 333727797783122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12917981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6458790 + 6458791.

It is an arithmetic number, because the mean of its divisors is an integer number (6458791).

Almost surely, 2^12917581 is an apocalyptic number.

It is an amenable number.

12917581 is a deficient number, since it is larger than the sum of its proper divisors (1).

12917581 is an equidigital number, since it uses as much as digits as its factorization.

12917581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 34.

The square root of 12917581 is about 3594.1036434694. The cubic root of 12917581 is about 234.6355055670.

The spelling of 12917581 in words is "twelve million, nine hundred seventeen thousand, five hundred eighty-one".