8020805521 has 4 divisors (see below), whose sum is σ = 8442953200. Its totient is φ = 7598657844.

The previous prime is 8020805519. The next prime is 8020805531. The reversal of 8020805521 is 1255080208.

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 a cyclic number.

It is not a de Polignac number, because 8020805521 - 2¹ = 8020805519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8020805531) 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, 211073811 + ... + 211073848.

It is an arithmetic number, because the mean of its divisors is an integer number (2110738300).

Almost surely, 2^8020805521 is an apocalyptic number.

It is an amenable number.

8020805521 is a deficient number, since it is larger than the sum of its proper divisors (422147679).

8020805521 is a wasteful number, since it uses less digits than its factorization.

8020805521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422147678.

The product of its (nonzero) digits is 6400, while the sum is 31.

The square root of 8020805521 is about 89558.9499770961. The cubic root of 8020805521 is about 2001.7322925647.

Adding to 8020805521 its reverse (1255080208), we get a palindrome (9275885729).

The spelling of 8020805521 in words is "eight billion, twenty million, eight hundred five thousand, five hundred twenty-one".