12891881 has 2 divisors, whose sum is σ = 12891882. Its totient is φ = 12891880.

The previous prime is 12891871. The next prime is 12891929. The reversal of 12891881 is 18819821.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9357481 + 3534400 = 3059^2 + 1880^2 .

It is a cyclic number.

It is not a de Polignac number, because 12891881 - 2¹⁴ = 12875497 is a prime.

It is a super-2 number, since 2×12891881² = 332401191436322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (12891811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6445940 + 6445941.

It is an arithmetic number, because the mean of its divisors is an integer number (6445941).

Almost surely, 2^12891881 is an apocalyptic number.

It is an amenable number.

12891881 is a deficient number, since it is larger than the sum of its proper divisors (1).

12891881 is an equidigital number, since it uses as much as digits as its factorization.

12891881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9216, while the sum is 38.

The square root of 12891881 is about 3590.5265630545. The cubic root of 12891881 is about 234.4797969511.

The spelling of 12891881 in words is "twelve million, eight hundred ninety-one thousand, eight hundred eighty-one".