12191321 has 4 divisors (see below), whose sum is σ = 12240144. Its totient is φ = 12142500.

The previous prime is 12191299. The next prime is 12191327. The reversal of 12191321 is 12319121.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12191321 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12191293 and 12191302.

It is not an unprimeable number, because it can be changed into a prime (12191327) 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, 24035 + ... + 24536.

It is an arithmetic number, because the mean of its divisors is an integer number (3060036).

Almost surely, 2^12191321 is an apocalyptic number.

It is an amenable number.

12191321 is a deficient number, since it is larger than the sum of its proper divisors (48823).

12191321 is an equidigital number, since it uses as much as digits as its factorization.

12191321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48822.

The product of its digits is 108, while the sum is 20.

The square root of 12191321 is about 3491.6072230421. The cubic root of 12191321 is about 230.1531494180.

The spelling of 12191321 in words is "twelve million, one hundred ninety-one thousand, three hundred twenty-one".