2085657561 has 27 divisors (see below), whose sum is σ = 3264970527. Its totient is φ = 1282385520.

The previous prime is 2085657517. The next prime is 2085657599. The reversal of 2085657561 is 1657565802.

The square root of 2085657561 is 45669.

It is a perfect power (a square), and thus also a powerful number.

2085657561 is a `hidden beast` number, since 2 + 0 + 85 + 6 + 5 + 7 + 561 = 666.

It can be written as a sum of positive squares in only one way, i.e., 308529225 + 1777128336 = 17565^2 + 42156^2 .

It is not a de Polignac number, because 2085657561 - 2¹¹ = 2085655513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2085657361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1780506 + ... + 1781676.

Almost surely, 2^2085657561 is an apocalyptic number.

2085657561 is the 45669-th square number.

2085657561 is the 22835-th centered octagonal number.

It is an amenable number.

2085657561 is a deficient number, since it is larger than the sum of its proper divisors (1179312966).

2085657561 is an equidigital number, since it uses as much as digits as its factorization.

2085657561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2374 (or 1187 counting only the distinct ones).

The product of its (nonzero) digits is 504000, while the sum is 45.

The cubic root of 2085657561 is about 1277.6571648302.

The spelling of 2085657561 in words is "two billion, eighty-five million, six hundred fifty-seven thousand, five hundred sixty-one".