12891181 has 4 divisors (see below), whose sum is σ = 12970432. Its totient is φ = 12811932.

The previous prime is 12891173. The next prime is 12891187. The reversal of 12891181 is 18119821.

12891181 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18119821 = 227 ⋅79823.

It is a cyclic number.

It is not a de Polignac number, because 12891181 - 2³ = 12891173 is a prime.

It is a super-2 number, since 2×12891181² = 332365095149522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12891187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39381 + ... + 39706.

It is an arithmetic number, because the mean of its divisors is an integer number (3242608).

Almost surely, 2^12891181 is an apocalyptic number.

It is an amenable number.

12891181 is a deficient number, since it is larger than the sum of its proper divisors (79251).

12891181 is an equidigital number, since it uses as much as digits as its factorization.

12891181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79250.

The product of its digits is 1152, while the sum is 31.

The square root of 12891181 is about 3590.4290829927. The cubic root of 12891181 is about 234.4755529666.

The spelling of 12891181 in words is "twelve million, eight hundred ninety-one thousand, one hundred eighty-one".