1591399 has 4 divisors (see below), whose sum is σ = 1595880. Its totient is φ = 1586920.

The previous prime is 1591397. The next prime is 1591417. The reversal of 1591399 is 9931951.

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

It is a cyclic number.

It is not a de Polignac number, because 1591399 - 2¹ = 1591397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1591391) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1657 + ... + 2434.

It is an arithmetic number, because the mean of its divisors is an integer number (398970).

2^1591399 is an apocalyptic number.

1591399 is a deficient number, since it is larger than the sum of its proper divisors (4481).

1591399 is an equidigital number, since it uses as much as digits as its factorization.

1591399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4480.

The product of its digits is 10935, while the sum is 37.

The square root of 1591399 is about 1261.5066389044. The cubic root of 1591399 is about 116.7507538922.

The spelling of 1591399 in words is "one million, five hundred ninety-one thousand, three hundred ninety-nine".