1081391 has 4 divisors (see below), whose sum is σ = 1128432. Its totient is φ = 1034352.

The previous prime is 1081369. The next prime is 1081403. The reversal of 1081391 is 1931801.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1081391 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 47017 = 1081391 / (1 + 0 + 8 + 1 + 3 + 9 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1081331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23486 + ... + 23531.

It is an arithmetic number, because the mean of its divisors is an integer number (282108).

2^1081391 is an apocalyptic number.

1081391 is a deficient number, since it is larger than the sum of its proper divisors (47041).

1081391 is an equidigital number, since it uses as much as digits as its factorization.

1081391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47040.

The product of its (nonzero) digits is 216, while the sum is 23.

The square root of 1081391 is about 1039.8995143763. The cubic root of 1081391 is about 102.6425856173.

The spelling of 1081391 in words is "one million, eighty-one thousand, three hundred ninety-one".