1311391 has 12 divisors (see below), whose sum is σ = 1428952. Its totient is φ = 1202256.

The previous prime is 1311383. The next prime is 1311403. The reversal of 1311391 is 1931131.

It is a happy number.

It is not a de Polignac number, because 1311391 - 2³ = 1311383 is a prime.

It is a pancake number, because a pancake can be divided into 1311391 parts by 1619 straight cuts.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311301) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19540 + ... + 19606.

2^1311391 is an apocalyptic number.

1311391 is a deficient number, since it is larger than the sum of its proper divisors (117561).

1311391 is an equidigital number, since it uses as much as digits as its factorization.

1311391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150 (or 127 counting only the distinct ones).

The product of its digits is 81, while the sum is 19.

The square root of 1311391 is about 1145.1598141744. The cubic root of 1311391 is about 109.4571324317.

The spelling of 1311391 in words is "one million, three hundred eleven thousand, three hundred ninety-one".