820897585 has 4 divisors (see below), whose sum is σ = 985077108. Its totient is φ = 656718064.

The previous prime is 820897573. The next prime is 820897607. The reversal of 820897585 is 585798028.

It is a happy number.

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 430479504 + 390418081 = 20748^2 + 19759^2 .

It is a cyclic number.

It is not a de Polignac number, because 820897585 - 2⁹ = 820897073 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 82089754 + ... + 82089763.

It is an arithmetic number, because the mean of its divisors is an integer number (246269277).

Almost surely, 2^820897585 is an apocalyptic number.

It is an amenable number.

820897585 is a deficient number, since it is larger than the sum of its proper divisors (164179523).

820897585 is a wasteful number, since it uses less digits than its factorization.

820897585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164179522.

The product of its (nonzero) digits is 1612800, while the sum is 52.

The square root of 820897585 is about 28651.3103539786. The cubic root of 820897585 is about 936.3315543369.

The spelling of 820897585 in words is "eight hundred twenty million, eight hundred ninety-seven thousand, five hundred eighty-five".