2085991805 has 8 divisors (see below), whose sum is σ = 2519991000. Its totient is φ = 1657592896.

The previous prime is 2085991777. The next prime is 2085991811. The reversal of 2085991805 is 5081995802.

It can be written as a sum of positive squares in 4 ways, for example, as 8637721 + 2077354084 = 2939^2 + 45578^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 2085991805 - 2⁸ = 2085991549 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2085991805.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1399250 + ... + 1400739.

It is an arithmetic number, because the mean of its divisors is an integer number (314998875).

Almost surely, 2^2085991805 is an apocalyptic number.

It is an amenable number.

2085991805 is a deficient number, since it is larger than the sum of its proper divisors (433999195).

2085991805 is a wasteful number, since it uses less digits than its factorization.

2085991805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2800143.

The product of its (nonzero) digits is 259200, while the sum is 47.

The square root of 2085991805 is about 45672.6592722605. The cubic root of 2085991805 is about 1277.7254129195.

The spelling of 2085991805 in words is "two billion, eighty-five million, nine hundred ninety-one thousand, eight hundred five".