1312391 has 2 divisors, whose sum is σ = 1312392. Its totient is φ = 1312390.

The previous prime is 1312379. The next prime is 1312393. The reversal of 1312391 is 1932131.

It is a strong prime.

It is an emirp because it is prime and its reverse (1932131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1312391 - 2¹⁰ = 1311367 is a prime.

Together with 1312393, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1312393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656195 + 656196.

It is an arithmetic number, because the mean of its divisors is an integer number (656196).

2^1312391 is an apocalyptic number.

1312391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1312391 is an equidigital number, since it uses as much as digits as its factorization.

1312391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 162, while the sum is 20.

The square root of 1312391 is about 1145.5963512512. The cubic root of 1312391 is about 109.4849475080.

The spelling of 1312391 in words is "one million, three hundred twelve thousand, three hundred ninety-one".