20202222221 has 4 divisors (see below), whose sum is σ = 21390588252. Its totient is φ = 19013856192.

The previous prime is 20202222217. The next prime is 20202222241. The reversal of 20202222221 is 12222220202.

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 12318558121 + 7883664100 = 110989^2 + 88790^2 .

It is a cyclic number.

It is not a de Polignac number, because 20202222221 - 2² = 20202222217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 1188366013 = 20202222221 / (2 + 0 + 2 + 0 + 2 + 2 + 2 + 2 + 2 + 2 + 1).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20202222221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20202222241) 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, 594182990 + ... + 594183023.

It is an arithmetic number, because the mean of its divisors is an integer number (5347647063).

Almost surely, 2^20202222221 is an apocalyptic number.

It is an amenable number.

20202222221 is a deficient number, since it is larger than the sum of its proper divisors (1188366031).

20202222221 is a wasteful number, since it uses less digits than its factorization.

20202222221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1188366030.

The product of its (nonzero) digits is 256, while the sum is 17.

Adding to 20202222221 its reverse (12222220202), we get a palindrome (32424442423).

The spelling of 20202222221 in words is "twenty billion, two hundred two million, two hundred twenty-two thousand, two hundred twenty-one".