12308991 has 4 divisors (see below), whose sum is σ = 16411992. Its totient is φ = 8205992.

The previous prime is 12308987. The next prime is 12308999. The reversal of 12308991 is 19980321.

12308991 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.

It is a cyclic number.

It is not a de Polignac number, because 12308991 - 2² = 12308987 is a prime.

It is a super-2 number, since 2×12308991² = 303022518876162, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12308999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2051496 + ... + 2051501.

It is an arithmetic number, because the mean of its divisors is an integer number (4102998).

Almost surely, 2^12308991 is an apocalyptic number.

12308991 is a deficient number, since it is larger than the sum of its proper divisors (4103001).

12308991 is an equidigital number, since it uses as much as digits as its factorization.

12308991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4103000.

The product of its (nonzero) digits is 3888, while the sum is 33.

The square root of 12308991 is about 3508.4171644775. The cubic root of 12308991 is about 230.8912552005.

The spelling of 12308991 in words is "twelve million, three hundred eight thousand, nine hundred ninety-one".