20575520289721 has 4 divisors (see below), whose sum is σ = 20963737653732. Its totient is φ = 20187302925712.

The previous prime is 20575520289707. The next prime is 20575520289733. The reversal of 20575520289721 is 12798202557502.

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 17697679473321 + 2877840816400 = 4206861^2 + 1696420^2 .

It is a cyclic number.

It is not a de Polignac number, because 20575520289721 - 2⁹ = 20575520289209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20575523289721) 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, 194108681926 + ... + 194108682031.

It is an arithmetic number, because the mean of its divisors is an integer number (5240934413433).

Almost surely, 2^{20575520289721} is an apocalyptic number.

It is an amenable number.

20575520289721 is a deficient number, since it is larger than the sum of its proper divisors (388217364011).

20575520289721 is an equidigital number, since it uses as much as digits as its factorization.

20575520289721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 388217364010.

The product of its (nonzero) digits is 7056000, while the sum is 55.

The spelling of 20575520289721 in words is "twenty trillion, five hundred seventy-five billion, five hundred twenty million, two hundred eighty-nine thousand, seven hundred twenty-one".