1991585 has 8 divisors (see below), whose sum is σ = 2419200. Its totient is φ = 1573744.

The previous prime is 1991573. The next prime is 1991597. The reversal of 1991585 is 5851991.

It is an interprime number because it is at equal distance from previous prime (1991573) and next prime (1991597).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1991585 - 2¹⁴ = 1975201 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1985 + ... + 2814.

It is an arithmetic number, because the mean of its divisors is an integer number (302400).

2^1991585 is an apocalyptic number.

It is an amenable number.

1991585 is a deficient number, since it is larger than the sum of its proper divisors (427615).

1991585 is an equidigital number, since it uses as much as digits as its factorization.

1991585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4887.

The product of its digits is 16200, while the sum is 38.

The square root of 1991585 is about 1411.2352745024. The cubic root of 1991585 is about 125.8151526541.

The spelling of 1991585 in words is "one million, nine hundred ninety-one thousand, five hundred eighty-five".