2185391885 has 16 divisors (see below), whose sum is σ = 2654331120. Its totient is φ = 1727109120.

The previous prime is 2185391869. The next prime is 2185391927. The reversal of 2185391885 is 5881935812.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 397962601 + 1787429284 = 19949^2 + 42278^2 .

It is not a de Polignac number, because 2185391885 - 2⁴ = 2185391869 is a prime.

It is a congruent 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 15 ways as a sum of consecutive naturals, for example, 956945 + ... + 959225.

It is an arithmetic number, because the mean of its divisors is an integer number (165895695).

Almost surely, 2^2185391885 is an apocalyptic number.

It is an amenable number.

2185391885 is a deficient number, since it is larger than the sum of its proper divisors (468939235).

2185391885 is a wasteful number, since it uses less digits than its factorization.

2185391885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4528.

The product of its digits is 691200, while the sum is 50.

The square root of 2185391885 is about 46748.1752050281. The cubic root of 2185391885 is about 1297.7063866832.

The spelling of 2185391885 in words is "two billion, one hundred eighty-five million, three hundred ninety-one thousand, eight hundred eighty-five".