12686991 has 8 divisors (see below), whose sum is σ = 16949424. Its totient is φ = 8441280.

The previous prime is 12686987. The next prime is 12687001. The reversal of 12686991 is 19968621.

12686991 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 12686991 - 2² = 12686987 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12686911) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2286 + ... + 5531.

It is an arithmetic number, because the mean of its divisors is an integer number (2118678).

Almost surely, 2^12686991 is an apocalyptic number.

12686991 is a deficient number, since it is larger than the sum of its proper divisors (4262433).

12686991 is an equidigital number, since it uses as much as digits as its factorization.

12686991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8361.

The product of its digits is 46656, while the sum is 42.

The square root of 12686991 is about 3561.8802618842. The cubic root of 12686991 is about 233.2309657536.

The spelling of 12686991 in words is "twelve million, six hundred eighty-six thousand, nine hundred ninety-one".