8205820509 has 4 divisors (see below), whose sum is σ = 10941094016. Its totient is φ = 5470547004.

The previous prime is 8205820507. The next prime is 8205820531. The reversal of 8205820509 is 9050285028.

8205820509 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 8205820509 - 2¹ = 8205820507 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8205820507) 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, 1367636749 + ... + 1367636754.

It is an arithmetic number, because the mean of its divisors is an integer number (2735273504).

Almost surely, 2^8205820509 is an apocalyptic number.

It is an amenable number.

8205820509 is a deficient number, since it is larger than the sum of its proper divisors (2735273507).

8205820509 is a wasteful number, since it uses less digits than its factorization.

8205820509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2735273506.

The product of its (nonzero) digits is 57600, while the sum is 39.

The square root of 8205820509 is about 90585.9840648651. The cubic root of 8205820509 is about 2017.0066855075.

The spelling of 8205820509 in words is "eight billion, two hundred five million, eight hundred twenty thousand, five hundred nine".