20001022221 has 4 divisors (see below), whose sum is σ = 26668029632. Its totient is φ = 13334014812.

The previous prime is 20001022213. The next prime is 20001022297. The reversal of 20001022221 is 12222010002.

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 20001022221 - 2³ = 20001022213 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20001022197 and 20001022206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001024221) 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, 3333503701 + ... + 3333503706.

It is an arithmetic number, because the mean of its divisors is an integer number (6667007408).

Almost surely, 2^20001022221 is an apocalyptic number.

It is an amenable number.

20001022221 is a deficient number, since it is larger than the sum of its proper divisors (6667007411).

20001022221 is an equidigital number, since it uses as much as digits as its factorization.

20001022221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6667007410.

The product of its (nonzero) digits is 32, while the sum is 12.

Adding to 20001022221 its reverse (12222010002), we get a palindrome (32223032223).

The spelling of 20001022221 in words is "twenty billion, one million, twenty-two thousand, two hundred twenty-one".