1985891 has 12 divisors (see below), whose sum is σ = 2166720. Its totient is φ = 1816080.

The previous prime is 1985887. The next prime is 1985897.

1985891 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1985891 - 2² = 1985887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1985897) 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, 42230 + ... + 42276.

It is an arithmetic number, because the mean of its divisors is an integer number (180560).

2^1985891 is an apocalyptic number.

1985891 is a deficient number, since it is larger than the sum of its proper divisors (180829).

1985891 is an equidigital number, since it uses as much as digits as its factorization.

1985891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154 (or 107 counting only the distinct ones).

The product of its digits is 25920, while the sum is 41.

The square root of 1985891 is about 1409.2164489531. The cubic root of 1985891 is about 125.6951351314.

The spelling of 1985891 in words is "one million, nine hundred eighty-five thousand, eight hundred ninety-one".