20202020221 has 4 divisors (see below), whose sum is σ = 20229581692. Its totient is φ = 20174458752.

The previous prime is 20202020203. The next prime is 20202020231. The reversal of 20202020221 is 12202020202.

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 12189264025 + 8012756196 = 110405^2 + 89514^2 .

It is a cyclic number.

It is not a de Polignac number, because 20202020221 - 2²³ = 20193631613 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 (20202020231) 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, 13779636 + ... + 13781101.

It is an arithmetic number, because the mean of its divisors is an integer number (5057395423).

Almost surely, 2^20202020221 is an apocalyptic number.

It is an amenable number.

20202020221 is a deficient number, since it is larger than the sum of its proper divisors (27561471).

20202020221 is an equidigital number, since it uses as much as digits as its factorization.

20202020221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27561470.

The product of its (nonzero) digits is 64, while the sum is 13.

Adding to 20202020221 its reverse (12202020202), we get a palindrome (32404040423).

The spelling of 20202020221 in words is "twenty billion, two hundred two million, twenty thousand, two hundred twenty-one".