1861885 has 4 divisors (see below), whose sum is σ = 2234268. Its totient is φ = 1489504.

The previous prime is 1861879. The next prime is 1861889. The reversal of 1861885 is 5881681.

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 1125721 + 736164 = 1061^2 + 858^2 .

It is a cyclic number.

It is not a de Polignac number, because 1861885 - 2⁷ = 1861757 is a prime.

It is a Duffinian number.

1861885 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1861889) by changing a digit.

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, 186184 + ... + 186193.

It is an arithmetic number, because the mean of its divisors is an integer number (558567).

2^1861885 is an apocalyptic number.

It is an amenable number.

1861885 is a deficient number, since it is larger than the sum of its proper divisors (372383).

1861885 is an equidigital number, since it uses as much as digits as its factorization.

1861885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 372382.

The product of its digits is 15360, while the sum is 37.

The square root of 1861885 is about 1364.5090692260. The cubic root of 1861885 is about 123.0224252412.

The spelling of 1861885 in words is "one million, eight hundred sixty-one thousand, eight hundred eighty-five".