1440391 has 2 divisors, whose sum is σ = 1440392. Its totient is φ = 1440390.

The previous prime is 1440379. The next prime is 1440403. The reversal of 1440391 is 1930441.

It is a balanced prime because it is at equal distance from previous prime (1440379) and next prime (1440403).

It is a cyclic number.

It is not a de Polignac number, because 1440391 - 2¹⁹ = 916103 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1440301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 720195 + 720196.

It is an arithmetic number, because the mean of its divisors is an integer number (720196).

2^1440391 is an apocalyptic number.

1440391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1440391 is an equidigital number, since it uses as much as digits as its factorization.

1440391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 1440391 is about 1200.1629056091. The cubic root of 1440391 is about 112.9345432377.

The spelling of 1440391 in words is "one million, four hundred forty thousand, three hundred ninety-one".