12491191 has 2 divisors, whose sum is σ = 12491192. Its totient is φ = 12491190.

The previous prime is 12491177. The next prime is 12491197. The reversal of 12491191 is 19119421.

It is a strong prime.

It is an emirp because it is prime and its reverse (19119421) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12491191 - 2⁵ = 12491159 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12491197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6245595 + 6245596.

It is an arithmetic number, because the mean of its divisors is an integer number (6245596).

Almost surely, 2^12491191 is an apocalyptic number.

12491191 is a deficient number, since it is larger than the sum of its proper divisors (1).

12491191 is an equidigital number, since it uses as much as digits as its factorization.

12491191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 648, while the sum is 28.

The square root of 12491191 is about 3534.2879056466. The cubic root of 12491191 is about 232.0249118612.

The spelling of 12491191 in words is "twelve million, four hundred ninety-one thousand, one hundred ninety-one".