2585185681 has 4 divisors (see below), whose sum is σ = 2784046132. Its totient is φ = 2386325232.

The previous prime is 2585185667. The next prime is 2585185693. The reversal of 2585185681 is 1865815852.

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 332734081 + 2252451600 = 18241^2 + 47460^2 .

It is a cyclic number.

It is not a de Polignac number, because 2585185681 - 2⁵ = 2585185649 is a prime.

It is a super-2 number, since 2×2585185681² = 13366370010494867522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2585185621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99430206 + ... + 99430231.

It is an arithmetic number, because the mean of its divisors is an integer number (696011533).

Almost surely, 2^2585185681 is an apocalyptic number.

It is an amenable number.

2585185681 is a deficient number, since it is larger than the sum of its proper divisors (198860451).

2585185681 is a wasteful number, since it uses less digits than its factorization.

2585185681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198860450.

The product of its digits is 768000, while the sum is 49.

The square root of 2585185681 is about 50844.7212697641. The cubic root of 2585185681 is about 1372.4522617804.

The spelling of 2585185681 in words is "two billion, five hundred eighty-five million, one hundred eighty-five thousand, six hundred eighty-one".