12191309 has 16 divisors (see below), whose sum is σ = 13653360. Its totient is φ = 10813440.

The previous prime is 12191299. The next prime is 12191327. The reversal of 12191309 is 90319121.

It can be written as a sum of positive squares in 8 ways, for example, as 1155625 + 11035684 = 1075^2 + 3322^2 .

It is a cyclic number.

It is not a de Polignac number, because 12191309 - 2¹² = 12187213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12191009) 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 15 ways as a sum of consecutive naturals, for example, 47309 + ... + 47565.

It is an arithmetic number, because the mean of its divisors is an integer number (853335).

Almost surely, 2^12191309 is an apocalyptic number.

It is an amenable number.

12191309 is a deficient number, since it is larger than the sum of its proper divisors (1462051).

12191309 is a wasteful number, since it uses less digits than its factorization.

12191309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400.

The product of its (nonzero) digits is 486, while the sum is 26.

The square root of 12191309 is about 3491.6055046354. The cubic root of 12191309 is about 230.1530739042.

The spelling of 12191309 in words is "twelve million, one hundred ninety-one thousand, three hundred nine".