1328391 has 12 divisors (see below), whose sum is σ = 1938768. Its totient is φ = 876384.

The previous prime is 1328387. The next prime is 1328407. The reversal of 1328391 is 1938231.

It is not a de Polignac number, because 1328391 - 2² = 1328387 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1328311) 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, 211 + ... + 1643.

It is an arithmetic number, because the mean of its divisors is an integer number (161564).

2^1328391 is an apocalyptic number.

1328391 is a deficient number, since it is larger than the sum of its proper divisors (610377).

1328391 is a wasteful number, since it uses less digits than its factorization.

1328391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1542 (or 1539 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 1328391 is about 1152.5584583873. The cubic root of 1328391 is about 109.9280797090.

The spelling of 1328391 in words is "one million, three hundred twenty-eight thousand, three hundred ninety-one".