12191271 has 4 divisors (see below), whose sum is σ = 16255032. Its totient is φ = 8127512.

The previous prime is 12191269. The next prime is 12191279. The reversal of 12191271 is 17219121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17219121 = 3 ⋅5739707.

It is a cyclic number.

It is not a de Polignac number, because 12191271 - 2¹ = 12191269 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12191279) 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, 2031876 + ... + 2031881.

It is an arithmetic number, because the mean of its divisors is an integer number (4063758).

Almost surely, 2^12191271 is an apocalyptic number.

12191271 is a deficient number, since it is larger than the sum of its proper divisors (4063761).

12191271 is an equidigital number, since it uses as much as digits as its factorization.

12191271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4063760.

The product of its digits is 252, while the sum is 24.

The square root of 12191271 is about 3491.6000630084. The cubic root of 12191271 is about 230.1528347769.

The spelling of 12191271 in words is "twelve million, one hundred ninety-one thousand, two hundred seventy-one".