12391271 has 4 divisors (see below), whose sum is σ = 12413544. Its totient is φ = 12369000.

The previous prime is 12391261. The next prime is 12391297. The reversal of 12391271 is 17219321.

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 12391271 - 2¹⁸ = 12129127 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12391271.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12391201) 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, 10280 + ... + 11421.

It is an arithmetic number, because the mean of its divisors is an integer number (3103386).

Almost surely, 2^12391271 is an apocalyptic number.

12391271 is a deficient number, since it is larger than the sum of its proper divisors (22273).

12391271 is an equidigital number, since it uses as much as digits as its factorization.

12391271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22272.

The product of its digits is 756, while the sum is 26.

The square root of 12391271 is about 3520.1237194167. The cubic root of 12391271 is about 231.4045807467.

The spelling of 12391271 in words is "twelve million, three hundred ninety-one thousand, two hundred seventy-one".