12891217 has 2 divisors, whose sum is σ = 12891218. Its totient is φ = 12891216.

The previous prime is 12891211. The next prime is 12891223. The reversal of 12891217 is 71219821.

It is a balanced prime because it is at equal distance from previous prime (12891211) and next prime (12891223).

It can be written as a sum of positive squares in only one way, i.e., 9296401 + 3594816 = 3049^2 + 1896^2 .

It is an emirp because it is prime and its reverse (71219821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12891217 - 2³ = 12891209 is a prime.

It is equal to p₈₄₂₆₆₅ and since 12891217 and 842665 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (12891211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6445608 + 6445609.

It is an arithmetic number, because the mean of its divisors is an integer number (6445609).

Almost surely, 2^12891217 is an apocalyptic number.

It is an amenable number.

12891217 is a deficient number, since it is larger than the sum of its proper divisors (1).

12891217 is an equidigital number, since it uses as much as digits as its factorization.

12891217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2016, while the sum is 31.

The square root of 12891217 is about 3590.4340963176. The cubic root of 12891217 is about 234.4757712324.

The spelling of 12891217 in words is "twelve million, eight hundred ninety-one thousand, two hundred seventeen".