1991185 has 8 divisors (see below), whose sum is σ = 2730816. Its totient is φ = 1365360.

The previous prime is 1991177. The next prime is 1991189. The reversal of 1991185 is 5811991.

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

It is not a de Polignac number, because 1991185 - 2³ = 1991177 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1991185.

It is not an unprimeable number, because it can be changed into a prime (1991189) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28411 + ... + 28480.

It is an arithmetic number, because the mean of its divisors is an integer number (341352).

2^1991185 is an apocalyptic number.

It is an amenable number.

1991185 is a deficient number, since it is larger than the sum of its proper divisors (739631).

1991185 is an equidigital number, since it uses as much as digits as its factorization.

1991185 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56903.

The product of its digits is 3240, while the sum is 34.

The square root of 1991185 is about 1411.0935475722. The cubic root of 1991185 is about 125.8067289730.

It can be divided in two parts, 19 and 91185, that added together give a square (91204 = 302²).

The spelling of 1991185 in words is "one million, nine hundred ninety-one thousand, one hundred eighty-five".