20011022221 has 16 divisors (see below), whose sum is σ = 21199028400. Its totient is φ = 18859929088.

The previous prime is 20011022197. The next prime is 20011022237. The reversal of 20011022221 is 12222011002.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 1713049321 + 18297972900 = 41389^2 + 135270^2 .

It is a cyclic number.

It is not a de Polignac number, because 20011022221 - 2⁷ = 20011022093 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 (20011022261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 269745 + ... + 335833.

It is an arithmetic number, because the mean of its divisors is an integer number (1324939275).

Almost surely, 2^20011022221 is an apocalyptic number.

It is an amenable number.

20011022221 is a deficient number, since it is larger than the sum of its proper divisors (1188006179).

20011022221 is a wasteful number, since it uses less digits than its factorization.

20011022221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66368.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 20011022221 its reverse (12222011002), we get a palindrome (32233033223).

The spelling of 20011022221 in words is "twenty billion, eleven million, twenty-two thousand, two hundred twenty-one".