820910909 has 24 divisors (see below), whose sum is σ = 1075688640. Its totient is φ = 611290368.

The previous prime is 820910879. The next prime is 820910921. The reversal of 820910909 is 909019028.

It is a de Polignac number, because none of the positive numbers 2^k-820910909 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820910929) 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 23 ways as a sum of consecutive naturals, for example, 299 + ... + 40520.

It is an arithmetic number, because the mean of its divisors is an integer number (44820360).

Almost surely, 2^820910909 is an apocalyptic number.

It is an amenable number.

820910909 is a deficient number, since it is larger than the sum of its proper divisors (254777731).

820910909 is a wasteful number, since it uses less digits than its factorization.

820910909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40869 (or 40856 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 38.

The square root of 820910909 is about 28651.5428729414. The cubic root of 820910909 is about 936.3366201796.

The spelling of 820910909 in words is "eight hundred twenty million, nine hundred ten thousand, nine hundred nine".