1800985 has 4 divisors (see below), whose sum is σ = 2161188. Its totient is φ = 1440784.

The previous prime is 1800979. The next prime is 1801003. The reversal of 1800985 is 5890081.

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

It can be written as a sum of positive squares in 2 ways, for example, as 582169 + 1218816 = 763^2 + 1104^2 .

It is a cyclic number.

It is not a de Polignac number, because 1800985 - 2⁹ = 1800473 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

1800985 is a lucky number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 180094 + ... + 180103.

It is an arithmetic number, because the mean of its divisors is an integer number (540297).

2^1800985 is an apocalyptic number.

It is an amenable number.

1800985 is a deficient number, since it is larger than the sum of its proper divisors (360203).

1800985 is an equidigital number, since it uses as much as digits as its factorization.

1800985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360202.

The product of its (nonzero) digits is 2880, while the sum is 31.

The square root of 1800985 is about 1342.0078241203. The cubic root of 1800985 is about 121.6662246392. Note that the first 3 decimals are identical.

The spelling of 1800985 in words is "one million, eight hundred thousand, nine hundred eighty-five".